Browse Topic: Springs

Items (1,580)
In the fast growing automotive sector, reliability & durability are two terms of utmost importance along with weight and cost optimization. Therefore it is important to explore new technology which has less weight, low manufacturing cost and better strength. It also seek for a quick, cost effective and reliable methodology for its design validation so that any modification can be made by identifying the failures. This paper presents the rig level real world usage pattern simulation methodology to validate and correlate the vehicle level targets for micro strain, wheel forces and displacement on suspension components like optimized Z spring, torque rods, pan hard rod & mounting brackets of newly developed air suspension for buses
Tangade, Atul BanduBabar, SunilBankar, Milind AchyutraoMehendale, RavindraDhumal, KailasBhusari, DeepakSonawane, RavindraShinde, Saurabh
December is a good time to reflect on the past year - to celebrate successes and consider opportunities for improvement - but it is also an opportune time to look to the future. As I think about the year ahead and appraise the tradeshow landscape that'll provide significant content for this magazine, mobilityengineeringtech.com, our e-newsletters and other multimedia products, none is bigger than Bauma in Munich, Germany, particularly in terms of the global construction and mining vehicle industries. The triennial event will cover an area that's equivalent to 86 soccer fields, according to Stefan Rummel, CEO of Messe München GmbH. Speaking to the press during an October virtual preview of Bauma 2025, which takes place from April 7-13, Rummel said that the number of exhibitors - expected to be about 3,600 - will be closer to the 2019 event versus the post-COVID-19 edition that was pushed back from its usual spring timeslot to the fall of 2022
Gehm, Ryan
ABSTRACT This paper presents the comparative analysis of virtual and experimental proving ground for the performance capabilities of front suspensions in the Family of Medium Tactical Vehicles (FMTV) cargo truck. The front suspension of the current baseline FMTV is a solid axle with leaf springs and shock absorbers. Two other types of suspensions including passive and semi-active suspensions are evaluated in solid and fully independent axle configurations. Virtual proving ground for on- and off-road tests are simulated in the Trucksim environment to include constant radius circular steer, double lane change, sinusoidal steer, washboard road surfaces, and half-round curb strike. Physical proving ground tests are conducted to provide some experimental correlation and validation of the baseline vehicle simulation results. The comprehensive experiments also evaluate the capabilities of various suspensions which have been considered in future FMTV design for mobility performance improvement
Liao, Y. GeneCard, BrandonWasylyk, John
ABSTRACT The analysis and design of a novel active suspension system incorporating a negative stiffness spring are investigated in this paper. The suspension structure consists of the mechanism that employs a combination of ordinary and negative stiffness springs and damping element. The resulting system yields superior performance in terms of mobility, maneuverability, and stability, particularly in harsh terrains and/or off-road environment. However, its dynamics are highly nonlinear and cannot be handled directly by conventional design techniques and methodologies. In this paper, the formulation of the proposed active suspension system consists of two phases: analysis and synthesis. In the analysis phase, nonlinear controls based on the advanced feedback linearization methodologies of the differential geometric theory is considered. The approach renders the difficult task of developing nonlinear controls rather simple. In the synthesis phase, which is required for real-world
Loh, Robert N. K.Thanom, WittBrock, Derrick
ABSTRACT A time-accurate multibody dynamics model of the suspension system of a tracked vehicle is experimentally validated using a full-scale tracked-vehicle on an N-post motion simulator. The experiments consist of harmonic excitations at various amplitudes and frequencies and ramp excitations of the vehicle road-wheels (without the track), with each road wheel under one linear actuator of the N-post motion simulator. A high-fidelity multibody dynamics model of the vehicle along with the N-post motion simulator is constructed. The multibody dynamics model consists of rigid bodies, joints, rotational springs (that include non-linear rotational stiffness, damping and friction), actuators and contact surfaces. The rigid bodies rotational equations of motion are written in a body-fixed frame with the total rigid-body rotation matrix updated each time step using incremental rotations. Connection points on the rigid bodies are used to define joints between the bodies including revolute
Wasfy, Tamer M.O’Kins, JamesRyan, David
In order to modify both stiffness and damping rates according to various road conditions, this research introduces a pneumatic spring in conjunction with a magnetorheological (MR) fluid damper as a single suspension unit for each wheel in the truck. Preventing weight transfer and improving riding comfort during braking, acceleration, and trajectory prediction are the main objectives. A two-axle truck has been used, consisting of three degrees of freedom for the sprung mass, including vertical, pitch, and roll motions, and four degrees of freedom for the unsprung masses, which have been redesigned according to the different types of springs and dampers. Pneumatic-controlled springs, often referred to as dynamic or classic models, replace laminated leaf springs commonly found in vehicles. Additionally, an MR damper replaces a hydraulic double-acting telescopic shock absorber. These models are studied to evaluate the effect of pneumatic spring parameters on truck dynamics. Pneumatic
Shehata Gad, AhmedEl-Zomor, Haytham M.
With the advent of electric and hybrid drivetrain in the commercial vehicle industry, electrically driven reciprocating compressors have gained widespread prominence. This compressor provides compressed air for key vehicle systems such as brakes, suspension systems and other auxiliary applications. To be a market leader, such an E-compressor needs to meet a myriad of design requirements. This includes meeting the performance by supplying air at required pressure and flow rate, durability requirements and having a compact design while maintaining cost competitiveness. The reed valve in such a compressor is a vital component, whose design is critical to meet the aforementioned requirements. The reed valves design has several key parameters such as the stiffness, natural frequency, equivalent mass, and lift distance which must be optimized. This reed valve also needs to open and close rapidly in response to the compressor operating speed. Since it is the order of milliseconds, the valve
J, BharadwajT, SukumarPendyala, Vamsi KrishnaPaul Pandian, Adheenthran
Automotive closure slam is the most crucial attribute affecting the closure structure and its mountings on BIW due to its high occurrence in real-world usage. Thus, virtual simulation of closure slam becomes necessary and is generally carried out using explicit codes with associated technical hitches like all-requisite inputs availability, FE modeling and analysis techniques, substantial human effort, high solution time, human and computational resource competence, or even access to suitable expensive explicit FE solver. Hence it becomes challenging to virtually analyze the design at every design phase of product development cycle under strict timelines leading to possibilities of both over- and under-designed parts, sometimes resulting in physical testing or even field failures. So, the need for an alternative simplified representation of closure slam, addressing the typical issues faced during explicit dynamic simulation and producing acceptable analysis outputs, gains significance
Chatterjee, Suprakash
This specification covers a carbon steel in the form of wire supplied as coils, spools, or cut lengths (see 8.2
AMS E Carbon and Low Alloy Steels Committee
Air spring systems are challenging to mathematically model due to the complexity of their nonlinear dynamic characteristics. Numerous air spring mechanical and thermodynamic models have been proposed, but this study focused on the development and analysis of a new thermodynamic air spring model under a polytropic thermodynamic process that could accurately represent the force output in a multibody dynamics (MBD) virtual suspension subsystem. This model considered function inputs of sprung mass, un-sprung mass, and design height to efficiently generate updated air spring properties for new vehicle configurations, specifically for a self-propelled sprayer application. After this model was validated against physical ground-truth sensor data, it was utilized in a sensitivity study to experimentally test an alternative air spring component and to understand the resulting performance effect on an operator comfort key performance indicator
Adams, Bailey
Tire forces and moments play an important role in vehicle dynamics and safety. X-by-wire chassis components including active suspension, electronic powered steering, by-wire braking, etc can take the tire forces as inputs to improve vehicle’s dynamic performance. In order to measure the accurate dynamic wheel load, most of the researches focused on the kinematic parameters such as body longitudinal and lateral acceleration, load transfer and etc. In this paper, the authors focus on the suspension system, avoiding the dependence on accurate mass and aerodynamics model of the whole vehicle. The geometry of the suspension is equated by the spatial parallel mechanism model (RSSR model), which improves the calculation speed while ensuring the accuracy. A suspension force observer is created, which contains parameters including spring damper compression length, push rod force, knuckle accelerations, etc., combing the kinematic and dynamic characteristic of the vehicle. Subsequently, the
Zeng, TianyiLiu, ZeyuHe, ChenyuZeng, ZimoChen, HaotianZhang, FeiyangFu, KaiChen, Xinbo
The soft and rough terrain on the planet's surface significantly affects the ride and safety of rovers during high-speed driving, which imposes high requirements for the control of the suspension system of planet rovers. To ensure good ride comfort of the planet rover during operation in the low-gravity environment of the planet's surface, this study develops an active suspension control strategy for torsion spring and torsional damper suspension systems for planet rovers. Firstly, an equivalent dynamic model of the suspension system is derived. Based on fractal principles, a road model of planetary surface is established. Then, a fuzzy-PID based control strategy aimed at improving ride comfort for the planet rover suspension is established and validated on both flat and rough terrains. This study provides an advanced suspension system control strategy for planet rovers' ride comfort and safety during high-speed driving, ensuring the smooth operation of vehicles on the rough
Liu, JunZhang, KaidiShi, JunweiWu, JinglaiZhang, Yunqing
A road test on semi-trailers is carried out, and accelerations of some characteristic points on the braking system,axles,and truck body is measured,also brake pressure and noise around the support frame is acquired.The measured data was analyzed to determine the causes of the brake noise, and the mechanism of the noise of the drum brake of semi-trailers during low-speed braking was investigated. The following conclusions are obtained: (1) Brake noise of the drum brake of the semi-trailer at low-frequency is generated from vibrations of the brake shoes, axle, and body, and the vibration frequency is close to 2nd natural frequency of the axle. (2) Brake noise is generated from stick-slip motion between the brake shoes and the brake drum, where the relative motion between the brake drum and the brake shoes is changed alternately with sliding and sticking, resulting in sudden changes in acceleration and shock vibration. A multi-body dynamic model of the semi-trailer is established for
Tang, HaoShangguan, Wen-BinKang, YingziZheng, Jing-YuanLan, Wen-Biao
In order to study the effects of different factors on the static and dynamic characteristics of air springs, three models were established to calculate the static and dynamic characteristics of air springs, including modeling at the design position, modeling only considering the straight state, and modeling considering the thickness of the bellows in the straight state. Static stiffness of air springs is calculated using three different models and are compared with experiments. In the straight state model considering the thickness of the bellow, the influence of aluminum tube and bellows thickness on the static stiffness are considered, and the modeling with the straight state solved the problem of the change in cord angle after the air spring was inflated and expanded. The established model is then used to calculate static and dynamic characteristics of air springs, such as static stiffness, hysteresis loop, and dynamic stiffness. The static stiffness, force versus displacement
Zhuo, Yi-FanWang, XihuiLi, JianxiangShangguan, Wen-Bin
The fatigue prediction model of an air spring based on the crack initiation method is established in this study. Taking a rolling lobe air spring with an aluminum casing as the studying example, a finite element model for analyzing force versus displacement is developed. The static stiffness and dimensional parameters of limit positions are calculated and analyzed. The influence of different modeling methods of air springs bellow are compared and analyzed. Static stiffness measurement of an air spring is conducted, and the calculation results and the measured results of the static stiffness are compared. It is shown that the relative error of the measured stiffness and calculated stiffness is within 1%. The Abaqus post-processing stage is redeveloped in Python language. The damage parameters including the maximum principal nominal strain, maximum Green-Lagrange strain, and effective stress of air spring bellows are extracted and calculated to find out the critical points, where the
Yu, YingjinYin, ZhihongLi, JianxiangShangguan, Wen-Bin
Leaf Springs are commonly used as a suspension in heavy commercial vehicles for higher load carrying capacity. The leaf springs connect the vehicle body with road profile through the axle & tire assembly. It provides the relative motion between the vehicle body and road profile to improve the ride & handling performance. The leaf springs are designed to provide linear stiffness and uniform strength characteristics throughout its travel. Leaf springs are generally subjected to dynamic loads which are induced due to different road profiles & driving patterns. Leaf spring design should be robust as any failure in leaf springs will put vehicle safety at risk and cost the vehicle manufacturer their reputation. The design of a leaf spring based on conventional methods predicts the higher stress levels at the leaf spring center clamp location and stress levels gradually reduce from the center to free ends of the leaf spring. In RWUP conditions, the failures of leaf spring can occur at the
Balasubramani, SritharkumarS Kangde, SuhasMohapatra, Durga PrasadM, Ayyappadas
The side-door operation of vehicle is vital to the customer, as it reflects the overall build quality of the vehicle. The side door check arm is one of the primary components that determine the operating characteristics of a vehicle door. The profile of the check arm has a significant impact on the closing effort of side doors. In this study, the check arm profiles are analyzed virtually in relation to the side door's closing velocity. A virtual door model was developed in ADAMS to simulate the side door closing and opening. The study involves a check arm that guides the ball spring mechanism housing unit over the guide profile. Typically, a check-arm guide profile has two or three indents at a specific location which serves to maintain the door open in those positions. When a door enters an indent, the user must exert an effort to traverse it. Furthermore, the slope profile of the check arm defines the self-closing assist offered from the initial indent to the latching position. By
Keshav T J, SharathSelvan, VeeraUnadkat, SiddharthSubbaiyan, Prasanna BalajiPandurangan, VenugopalNizampatnam, Balaramakrishna
This specification covers tubular-shaped pins, fabricated from carbon steel, having a full-length longitudinal slot to permit flexure when inserted into a hole
E-25 General Standards for Aerospace and Propulsion Systems
This procurement specification covers tubular-shaped, coiled spring pins made of a corrosion resistant nickel base alloy of the type identified under the Unified Numbering System as UNS N07718
E-25 General Standards for Aerospace and Propulsion Systems
Innovators at NASA’s Johnson Space Center have designed a circumferential scissor spring mechanism, that when incorporated into a hand controller, improves the restorative force to a control stick’s neutral position. The design also provides for operation on a more linear portion of the spring’s force deflection curve, yielding better feedback to the user. Physical hand controllers, such as translational and rotational controllers, use a non-circumferential scissor spring arrangement to return the control stick to a neutral position, but the linear response of a typical scissor spring arrangement can reduce a user’s sense of control by allowing slack between deflections
Load-carrying transportation has recently increased due to cargo and online home shopping. As a result, there is a growing demand for vehicles that can pass through narrow streets and carry loads for short distances. Electric vehicles are vital in the automotive industry due to their zero emissions and further promotion through new regulations. This study is focused on determining the spring coefficients of helical springs for a micro-truck vehicle, which will be used for cargo transportation and has a leaf spring with a specific spring coefficient on the rear axle and an independent double wishbone suspension system on the front axle. In addition to being vehicles with low weight values, micro-trucks have the axle capacity required for urban transportation due to their low track width and dimensions. Correctly determining the leaf spring is essential as it will directly affect the loads on the suspension system, wheel life, energy consumption, and comfort level. When determining the
Canpolat, BerkanAkbaba, MahirÇifci, ErolDoğan, Mehmet Ali
In recent years due to significant increased cost of raw material, fuel and energy, vehicle cost is increased. As vehicle cost is one of the major factors that attracts prospective buyers, it has created specific demand for low weight and low-cost components than traditional components with better performance to meet customer expectations. Suspension is one of the critical aggregates where lot of material is used and reduction in weight tends to give lot of cost benefit. As suspension system derives vehicle’s handling performance, it has to be ensured that handling performance of vehicle is maintained the same or made better while reducing weight of the suspension. Advancements in simulation capabilities coupled with manufacturing technology has enabled development non-traditional leaf springs. One of such springs is mono-leaf spring without shackle. This type of leaf spring provides advantages such as low weight and nonlinear stiffness. Hence, this type of spring can cater the need of
Pandhare, Vinay RamakantTiwari, ChaitanyaDeore, YogeshKhandekar, Dhiraj
In the modern automotive sector, durability and reliability are the most common terms. Customers are expecting a highly reliable product but at low cost. Any product that fails within its useful life leads to customer dissatisfaction and affects the reputation of the OEM. To eradicate this, all automotive components undergo stringent validation protocol, either in proving ground or in lab. This paper tails on developing an accelerated lab test methodology for NRS leaf spring bracket by simulating field failure. Initially, potential failure causes for spring bracket were analyzed. Road load data was then acquired at proving ground and customer site to evaluate the damage on the spring bracket. To simulate the field failure, lab test facility was developed, reproducing similar boundary conditions as in vehicle. Field failure was simulated with the existing design samples and Improved design of spring bracket was validated in the same test conditions and compared with the life of existing
G, ManthiramoorthyNarasimman, Obuli KarthikeyanNagarajan, GopikannanR, Suresh
A measurement for a Commercial Vehicle Manufacturer was executed to compare and monitor the behaviors of a Heavy-Duty Vehicle with a real-life standard load on a private proving ground and on real road. During this measurement an event of Trailer Hoist-up was captured and recorded. Suspension springs arch open when the weight of the truck is put on them, while theoretically possible, it is improbable the springs would arch the other way around. It would require the vehicle to be suspended for a small fraction of time, which is rare on real road application because of the mass inertia of Heavy-Duty Vehicles. A Trailer Hoist-up produces an interesting particular situation for the spring. The strain distribution on the spring during the event was measured by the strain gauges mapped as a grid. The implications on the vehicle were measured by wheel force transducers, equipped with triaxial forces and triaxial moments, speed and position. Likewise, vehicle CAN bus data was recorded and its
Onuki, Ciro
Manufacturing suspension systems is not a new or upcoming process, it has been in the market for years but still, the survival of the fittest plays a key role for the respective manufacturer. So, the main objective of the vehicle suspension system is to improve ride comfort, road handling and vehicle stability. A suspension system plays a vital role in a smooth and safe riding experience. So, an analysis of the suspension system should be done, and the results should be in the standard range. In this paper, the simulations of a quarter and half car passive spring and air suspension were analysed for ride comfort and suspension travel by mathematical modelling of the quarter-and-half car with the help of a system of equations. As these mathematical equations cannot be solved directly, these equations are solved with the help of library blocks of MATLAB/ Simulink software by giving different road profiles as single bumps, step functions and irregular road profiles as excitations for the
B, Vamsi Surya.T, SukumarRajarethinam, PravinpandianSundarrajan, Srinivasan
In manual transmission, the vital function of synchronizer pack is to synchronize the speed of the target gear for smooth gear shifting. The synchronizer pack consists of various elements and each of these elements has specific function. These elements are baulk rings, shifter sleeve, hub, synchro key, synchro springs etc. The function of synchronizer can be affected due to failure of any one of these elements. This work focuses on the failure of synchronizer pack due to synchro spring failure. The function of synchronizer spring is to exert the required force, to index the synchronizer ring before the movement of shifter sleeve over synchronizer ring. During the shifting of shifter sleeve from one gear to another gear, the springs deflect in both shifting directions. This causes fatigue failure of synchronizer springs. The manufacturing variations, and part quality issues results in very early fatigue failure of synchronizer springs. The failure of synchronizer springs affects the
JAMADADE, GAJANANK, Barathi RajaChatterjee, Soumik
This paper focuses on a low-cost simulation of a control device that automates the operation of an existing suspension test rig. The rig has a few limitations: it must be manually controlled, the load applied cannot be specified, and the deflection must be manually measured. A suspension setup can't be checked for different road profiles, either. The proposed control system in this paper effectively automates the process of suspension spring load testing at a cost that is comparable to that of a fully automated test rig on the market, while also expanding the scope of its capabilities. SIMSCAPE was used to map simulation models of both the actual test rig and the updated test rig control system. On both rigs, the results of evaluating suspension components were simulated, and the resulting graphs were compared
Kumar, V SudhirPasupuleti, ThejasreeNatarajan, Manikandan
Innovators at NASA Johnson Space Center have designed a circumferential scissor spring mechanism, NASA engineers have developed a new approach to mitigating unwanted structural vibrations. NASA’s method is fundamentally different from conventional passive and active vibration damping methods widely used today. Tension Element Vibration Damping uses disruptive modal coupling between two structures, each with their own vibrational behavior, to proactively provide vibration damping for one or both of the structures
Laser powder bed fusion is one of the metal additive manufacturing technologies, so-called 3D printing. It has attracted great attentions due to high geometrical flexibility and remarkable metallurgical characteristics. An oil catch tank has been widely used in automotive industries for filtering oil vapors or carbon sludge from blow-by gas as a conventional usage. A pneumatic valve system mainly adopted to high-performance engines is also a potential application of it because undesirable oil infiltrates into air springs during engine operation, resulting in an excess spring pressure. This work focused on developing a lightweight oil catch tank which can be applied to a pneumatic valve system by taking advantage of additive manufacturing techniques. Al-Mg-Sc alloy powder with high tensile strength as well as high ductility were used under the consideration of specific strength, printability and availability. Test specimens fabricated with optimal printing parameters exhibited
Watanabe, KeitaKurita, HirotakaIwasaki, ShinyaMitsui, RikuNagao, TakashiTashiro, TsuguharuIchimura, MakotoKano, YoshiakiKusui, Jun
In this article, the effect of heat treatment on the microstructure and mechanical behavior of medium-carbon steel wire intended for the spring mattress is investigated using scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), X-ray diffraction, Vickers hardness (Hv), and tensile strength. The results indicate that the microstructure elongation along the wire axis is observed with the bending and kinking lamellae at the deformation level of 57.81%, this change appears as a fracture in the microstructure and leads to an increase in hardness, tensile strength, and intensities of diffraction patterns. After heat treatment, we observed a redistribution in the grain, which is almost the same in the wire rod and drawn wires; indeed, this led to a decrease in hardness, tensile strength, and augmentation in intensities of peaks. The EBSD pole figures reveal the development of texture in the cementite slip plane (001
Ourabi, AminaZidani, MosbahMessaoudi, SalimAbid, TaharNebbar, Mohamed ChaoukiBrisset, FrançoisBaudin, Thierry
First, a particular type of microbe evolved in an acidic hot spring. Fast-forward millions of years, when a geomicrobiologist finds this type of microbe in Yellowstone National Park while conducting NASA-funded research on organisms that thrive under extreme conditions
At John Deere's inaugural Tech Summit this past spring in Austin, Texas - the location of one of the company's micro-technology hubs and a recently purchased farm on which to conduct R&D activities - sustainability and innovation were two of the overarching topics expounded by various executives. John Deere is providing the executive leadership for this year's SAE COMVEC conference, scheduled for September 19-21 in Schaumburg, Illinois. Not coincidentally, the theme for the 2023 iteration is “Sustainability: The New Frontier for Innovation
Gehm, Ryan
The measurement of the cargo weight on semi-trailer trucks is required to several stakeholders in the logistics market, for this information can reduce expenses on vehicle maintenance, risk for load traffic fines and ensures safer driving of the vehicle. The state-of-the-art on on-board weighing systems of semi-trailers with leaf spring suspension adopt several techniques to estimate the load: solutions based on load cells, vibrating-wires force transducers or strain gauges on the chassis, on the suspension springs or on the axles of the vehicle. In this work, a new system based on hall effect sensor was developed and tested for measurement of the axle load in semi-trailers through the linear movement that occurs between the trailer axle and its chassis. This solution has low sensitivity to environmental phenomena not caused by human intervention, such as humidity or temperature variations. A lab test was made to compare some arrangements of magnets and hall effect sensors to find out
Parigot, AugustoWeschenfelder, ArthurSeibert, ArturLampert, Luis PedroVeras, RafaelZanolli, Willians
Vehicle suspension systems that adopt Hotchkiss layout are commonly based on leaf springs. For better comfort for passengers, some features such as rubber pads are used on the springs to reduce noise from metallic contact between leaves, but those pads can compromise the durability of the spring if not well designed or located in the spring assembly, as we will demonstrate on this paper. To do so, it will be presented comparisons using CAE methodology and physical parts test results from vehicle and bench testing which were loaded in different conditions to demonstrate how the rubber pad position can influence the durability of the spring, especially near the eyelet region for some specific load conditions. The case studies presented here are focused on the impact of the rubber pads on durability life of springs, but not defined as root cause of failures
Belli, Milton Monteverdeda Cunha Fernandes, Ricardo Alexandreda Costa, Mateus CesárioManini, Ricardo Guedes
Improvements in component/system design is a daily challenge these days, always looking for high performance, reduced mass and low costs. The source for the best fit between these factors, coupled with adequate durability performance, is crucial to the success of a given product and this is what motivates engineering teams around the world. The demand for efficient projects with short deadlines for validation and certification is huge and simulation tools focused on accelerated durability and virtual validation are increasingly being used. When developing a new spring for commercial vehicles, lessons learned from the actual loads applied to the suspension are the “key” to a successful project. The loads/stresses from the ground (vertical loads, lateral loads, longitudinal and braking loads) are quite high and, consequently, relevant to the proper definition of the design of the suspension components. The objective of this work is to describe the main development activities faced during
de Oliveira dos Reis, Rodrigodos Santos, Raphael Otavio Silvade Souza, Vitor Braga FerreiraManenti, Vangelo CardosoLessa, Fabricio FaicalSaveljevas, Igor Rodriguesda Silva Santiago, CaioBanba, Claudio MitsuoPfeifer, Luciano
This work deals with the effect of different blasting conditions under stress on the intensity and distribution of compressive residual stresses. The tests were performed on bars measuring 17 mm x 70 mm x 1700 mm in AISI 51CrV4 carbon steel. The samples are considered parabolic leaf spring, as there is a variation in thickness from the tip to the center, the thickness ay the center is higher than tip thickness. The samples were laminated to their thickness in double roller laminators, in order to obtain the desired thicknesses. The samples were quenched and tempered in industrial scale furnaces. The pre-tensions were calculated by the ANSYS® software and validated by characterization with strain gauges, in a test condition of 1400 MPa of pre-tension. Tensile tests and microstructure analysis were applied to ensure the specification in terms of strength and microstructure. The stress shot peening process was performed on a sample with flexural load at two points with a support distance
Chiqueti, Cleber MichelManini, Ricardo GuedesGomes, Bárbara Mirandados Santos, Marcos
The lightweight structure of a semitrailer composite leaf spring is designed and manufactured using glass fiber composite to replace the conventional steel leaf spring. The sliding composite mono leaf spring was designed based on the conventional parabolic spring design theory. The composites product design (CPD) module of CATIA software is used to create the lamination of the composite leaf spring. Using finite element analysis of the position and proportion of ±45° biaxial layer by OptiStruct software, it is found that a certain proportion (nearly 5%) of a ±45° biaxial layer can effectively reduce the shear stress under the condition of keeping the total number of layers fixed. Then, the natural frequency, stiffness, and strength of the composite leaf spring are simulated by the finite element method. Finally, the stiffness, fatigue, and matching of the designed spring are tested by experiments. The design weight of the composite leaf spring is 18.5 kg, which is 55.4% lighter than
Wang, LubinZhu, ChendiLu, XiaoqinZhang, ZhengpengLiang, Shiwen
Leaf springs are used for vehicle suspension to support the load. These springs are made of flat sections of spring steel in single or in stack of multiple layers, held together in bracketed assembly. The key characteristics of leaf spring are defined as ability to distribute stresses along its length and transmit a load over the width of the chassis structures. The most common leaf spring steels are carbon steels alloyed with Cr and micro-alloyed with Ti, V and Nb. The specific thermomechanical process and alloying elements result in specific strength and fatigue properties for spring steels. The unique properties which facilitate use of spring steel in leaf spring suspensions are ability to withstand considerable twisting or bending forces without any distortion. The microstructure of these steel determines the performance and reflects the process of steel manufacturing. The performance is mainly determined by evaluating fatigue life durability. The microstructural phases mainly
Chauhan, ShivShende, DeodattaDhadange, RaviPonkshe, Shripadraj
Engineering of solutions for vibration challenges consists of several steps. Each of them needs different methods, for most steps, several approaches are valid. This work describes one efficient way to get from customer wishes over calculation methods and experimental results as far as the lifetime calculation. The example is an all-metal cushion used as a spring-damper system, that solves vibration problems of the suspension of an electrical drive for a commercial vehicle used in a city. Metal cushions for vibration isolation are used where high dynamic stresses occur or the environmental conditions overwhelm rubber solutions. So, they are a perfect solution for vibration isolation in industrial environments as well as in railway, automotive and aerospace sectors. Additionally, the progressive stress-deflection behavior and the high damping offer advantages for a wide range of applications. A Design of Experiment was necessary to define the parameters for an analytical equation to
Schroth, RuedigerWirz, Alexander
Air springs with auxiliary chambers (ASAC) are widely used in automotive suspension systems. The introducing of the auxiliary chamber and the connecting flow passage makes the system more complex, especially in which case an additional resonance peak caused by the air inertia in a connecting pipe appears. To characterize the nonlinear dynamic characteristics, this paper proposes a novel physical-neural network hybrid modeling method for ASACs. Firstly, experiments are carried out to measure the dynamic characteristics of ASACs. Then, based on the thermodynamic principle, a nonlinear dynamic characteristic model for the ASAC is developed and a linearized process is performed to obtain a linearized physical model. Due to the amplitude dependence and frequency dependence in the dynamic characteristics of ASACs, the physical model cannot accurately characterize these nonlinearities. To compensate for the errors caused by the uncaptured frictional damping and nonlinear air resistance, a
Zheng, YiqianShangguan, Wenbin
When commercial vehicles have less than ideal lateral dynamics traveling at high speeds, those dynamics can sometimes be a significant factor in serious and fatal accidents that occur. The primary goal of this study was to create a validated vehicle dynamics model to aid in handling evaluations and a validated model that can play an important role in accurately predicting the movement of the vehicle in limit conditions. The model is used to simulate the effect on roll gradient by altering spring stiffnesses and adding a rear stabilizer for a class 6 or class 7 commercial vehicle (CV). Outputs from 4-post Kinematics & Compliance (K&C) tests of a prototype vehicle were used to model the suspension system. The tire model was developed in collaboration with Calspan [1] using physical tire testing. The vehicle masses, inertias and stiffnesses were modelled using IPG TruckMaker for Simulink (TM4SL) [2]. A constant radius turn maneuver was simulated using TM4SL, and MATLAB [3] was used for
Obel, LukasEdla, NitinPasupathi, SanthoshBergsieker, Gerald
Many vehicles have been equipped with air springs as elastic elements to get better performance in comfort, but absorbers may not work in an optimal state due to the variation of suspension stiffness. While the function of semi-active suspension is to enable the absorber damping to be adjusted according to different road roughness levels and to coordinate between comfort and handling. To solve the problem of matching the damping coefficient of variable stiffness suspensions represented by air springs, this paper proposed a method for calculating the optimal damping ratio of a semi-active suspension system in real-time with sprung mass acceleration and dynamic tire load to establish the objective function and suspension dynamic deflection as the constraint to reflect the unification of comfort and handling. The effectiveness of the proposed damping calculated method is validated by comparing it with classical methods including passive suspension and shy-hook control on straight roads
Zhu, QingxiaoChen, ZixuanYu, DongLao, ZhenhaiZhang, Yunqing
When a turbocharger exhaust-driven turbine wheel spins fast enough to produce the desired level of boost, a wastegate is typically used to allow the excess exhaust pressure to divert around the turbine wheel. By opening the wastegate (typically boost-pressure referenced), exhaust pressure bypasses the turbo’s turbine wheel to prevent the turbo from reaching an unsafe speed. To actuate wastegate, different actuating mechanisms like pneumatic, vacuum or electric are available, which regulates poppet valve positions e.g. full close, open or partially open. In electronic wastegate valve, exhaust pressure pass through the bypass hole collides with the face of valve causing vibration. Such vibration is transmitted to the wastegate components causing rattle noise. It is challenging to design a wastegate mechanism which can sustain wastegate loads at high temperature and give quiet and robust performance within the full operating range of the engine. In order to improve the rattle noise, the
Patel, Lala RamBaladhandapani PhD, DhanasekarDu, Isaac
Taking a closed airbag suspension system as studying objects, the nonlinear dynamic model of the reservoir, compressor, solenoid valve, pipeline and air spring is established. The compressor exhaust volume, solenoid valve flow rate and air spring charging and discharging rate are calculated and compared with experiment to validate the model. Taking pressure difference and height adjustment rate under different working conditions of an airbag suspension as control measures, a control strategy is developed based on the established nonlinear dynamic model. The result indicates that when the vehicle is in curb weight, design weight and GVW (gross vehicle weight), the working time of the compressor can be reduced by 13.6%, 15.1% and 46.5%, respectively, compared with the conventional mode, during a height adjustment cycle. Then a state observer is proposed to estimate the steady-height for reducing the disturbance of measured height from road excitation. According to the required height
Deng, LinLv, HuiShangguan, Wenbin
The Brake judder is a low-level vibration caused due to Disc Thickness Variation (DTV), Temperature, Brake Torque Variation (BTV), thermal degradation, hotspot etc. which is a major concern for the past decades in automobile manufacturers. To predict the judder performance, the modelling methods are proposed in terms of frequency and BTV respectively. In this study, a mathematical model is constructed by considering full brake assembly, tie rod, coupling rod, steering column, and steering wheel as a spring mass system for identifying judder frequency. Simulation is also performed to predict the occurrence of brake judder and those results are validated with theoretical results. Similarly, for calculating BTV a separate methodology is proposed in CAE and validated with experimental and theoretical results
S, GurumoorthyBhumireddy, YugandharBourgeau, AlyssaBhimchand, Naresh
A vehicle must be designed in such a way that it guarantees its occupants safety and comfort in the face of various situations, such as a sudden lane change, something that can happen at any time during a trip or even a military operation. In this situation, the car must react to this excitement without compromising the car's stability. In this context, the present work aims to study the application of semi active suspension with magnetorheological dampers assisted by an embedded electronics system in order to improve the dynamic behavior of the vehicle, whose suspension springs are modeled in a non-linearly way using polynomials. To this end, this study performs an analysis of the vertical and lateral dynamics of a 4 x 4 vehicle with 10 degrees of freedom. The model construction uses the power flow methodology to establish the relationship between the kinematics and the dynamics of the chassis. The computational implementation was made utilizing block diagram methodology, using one
dos Santos Belle, Vilson Wenisda Costa Neto, Ricardo Teixeira
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