Browse Topic: Springs

Items (1,600)
For the diesel engines first designed & developed before 2000s, push-rod type valvetrains with mechanical valve lash adjustment were common. For one such legacy diesel engine, first developed for tractors and now applicated for on road vehicles, having push-rod valvetrain architecture & mechanical valve lash adjustment (Type-5 valvetrain system) with flat follower tappet, integrating HLAs for enhancing the NVH & serviceability presented certain challenges. This paper delves into the challenges faced in the design & development phase of HLA integration project on a four-cylinder diesel engine. For integration of HLA, first, the packaging evaluation of valvetrain assembly was done followed by oil flow assessment and necessary changes in the oil pump and circuit. Then, valve lift profile optimizations were done since the ramp rate & seating velocity requirements are different for valvetrains with mechanical lash and HLAs. Numerous iterations were performed for cam-profile design to
John, Shijino ShajiBagal, Pratik
This article presents a novel mechanical model for simulating the behavior of pavement deflection measuring systems (PDMS). The accuracy of the model was validated by comparing the acceleration of the new model with the data achieved through experimental tests fusing a deflection measurement system mounted on a Ford F-150 truck. The experimental test for the PDMS is carried out on a random road profile, generated by an inertial profiler, over a 7.4-mile (12 km) loop around a lake near Austin, Texas. Integrating a reliability-based optimization (RBO) algorithm in a PDMS aims to optimize system parameters and reduce vibrations effectively. The PDMS noises and uncertainties make it crucial to use a robust system to ensure the stability of the system. This article presents a robust algorithm for considering the uncertainties of PDMS parameters, including the damping coefficients and spring stiffness of the supporting brackets. Moreover, it considers the variation of system parameters, such
Yarmohammadisatri, SadeghSandu, CorinaClaudel, Christian
It is widely common for commercial vehicles to use Hotchkiss suspension with leaf springs attached to the solid axles. This configuration is cost effective and robust enough for the required application. The leaf springs evolved in the past decades in terms of new materials and construction, and the validation methods also changes. Since the application can be aggressive in some markets, physical tests are done to validate their durability and performance. Looking for a way to reduce development time and costs, high confidence level virtual validations are targeted by the whole industry. Using FEA fed by road load data as inputs for the loads applied to the leaf springs is an evolving methodology that can be considered as a high confidence level validation method, achieving very representative results, allowing engineering team to dismiss physical tests and release the item for production. The stages of spring development will be described in this paper, focusing on the virtual
Belli, Milton Monteverdeda Costa, Mateus Cesário
The continuous improvement of validation methodologies for mobility industry components is essential to ensure vehicle quality, safety, and performance. In the context of mechanical suspensions, leaf springs play a crucial role in vehicle dynamics, comfort, and durability. Material validation is based on steel production data, complemented by laboratory analyses such as tensile testing, hardness measurements, metallography, and residual stress analysis, ensuring that mechanical properties meet fatigue resistance requirements and expected durability. For performance evaluation, fatigue tests are conducted under vertical loads, with the possibility of including "windup" simulations when necessary. To enhance correlation accuracy, original suspension components are used during testing, allowing for a more precise validation of the entire system. Additionally, dynamic stiffness measurements provide valuable input for vehicle dynamics and suspension geometry analysis software, aiding in
Zahn, André N.Graebin, MatheusMalacarne, RodrigoToniolo, Juliano C.
Advanced motion control technologies are essential to modern aerospace design, supporting a wide range of safety-critical and comfort-driven applications. In aerospace, motion control components such as gas springs, actuators, and dampers are integral to nearly every commercial aircraft, rocket, satellite, and space vehicle. These critical elements support flight safety and transport functions, from the dependable deployment of landing gear and cargo doors to the smooth, ergonomic operation of seating for pilots and passengers.
This research presents a semi-active suspension system that combines an air spring and a magneto-rheological (MR) fluid damper to produce both active force and variable damping rates based on the road conditions. The suspension system used for the military light utility vehicle (MLUV) has seven degrees of freedom. A nonlinear model predictive control system generates the desired active force for the air spring control signal, while the linear quadratic regulator (LQR) estimates the target tracking of the intended damping force. The recurrent neural network is designed to develop a controller for an identification system. To achieve the optimal voltage for the MR damper without log time, it is used to simultaneously determine the active control force of the air spring by modifying the necessary damping force tracking. The MLUV suspension system is integrated with the traction control system to improve overall vehicle stability. A fuzzy traction controller adjusts the throttle angle
Shehata Gad, Ahmed
The article introduces the air springs, CDC, rear-wheel steering system, braking system, front-wheel steering system, and electric drive system in the vehicle’s central coordinated motion control system. It explores achieving more comfortable shock absorption by adjusting the CDC (Continuously Variable Damping system) damping and other means. By combining open-loop and closed-loop rear-wheel steering control, the turning radius in small-radius steering mode is reduced by up to 10%, enabling crab-walking, optimizing the moose test entering speed up to 90.9 kph, and improving vehicle behavior on split-friction surfaces. Through the cooperation of IBS (Intelligent Brake System) and VMC, an extremely comfortable braking process is achieved.
Zhou, YuxingLi, Wen
A vehicle powertrain system with a two-stage spring isolator separating a combustion engine from a transmission can exhibit significant nonlinear dynamics if the input torques cause the spring to continuously alternate between its first-stage and second-stage stiffnesses. In particular, this nonlinearity can result in subharmonic resonance of the system’s natural frequencies at half the frequency of the engine’s primary excitation order. A 1D torsional vibration model was prepared using Siemens’s Simcenter Amesim software to study these nonlinear vibrations. First, a correlated vehicle-level model was developed to replicate a half-order torsional resonance that was measured in a test of a research vehicle. Then, simplified theoretical models were used to study and demonstrate the sensitivity of this kind of subharmonic resonant response to changes in mean input torque level, amplitude of input torque oscillation, first-stage capacity of the spring isolator, and other factors.
Villiger, Jacob
Road noise caused by road excitation is a critical factor for vehicle NVH (Noise, Vibration, and Harshness) performance. However, assessing the individual contribution of components, particularly bushings, to NVH performance is generally challenging, as automobiles are composed of numerous interconnected parts. This study describes the application of Component Transfer Path Analysis (CTPA) on a full vehicle to provide insights into improving NVH performance. With the aid of Virtual Point Transformation (VPT), blocked forces are determined at the wheel hubs; afterward, a TPA is carried out. As blocked forces at the wheel hub are independent of the vehicle dynamics, these forces can be used in simulations of modified vehicle components. These results allow for the estimation of vehicle road noise. To simulate changes in vehicle components, including wheel/tire and rubber bushings, Frequency-Based Substructuring (FBS) is used to modify the vehicle setup in a simulation model. In this
Kim, JunguReichart, Ronde Klerk, DennisSchütler, WillemMalic, MarioKim, HyeongjunKim, Uije
The recent addition of fully electric powertrains to propulsion system options has increased the relevance of sound and vibration from electric motors and gearboxes. Electrified beam axles require different metrics from conventional beam axles for noise and vibration because they have multiple sources of vibration energy, including an electric motor and a reduction gearbox. Improved metrics are also driven by the stiff suspension connections and lack of significant isolation compared to electric drive units. Blocked force is a good candidate because it can completely characterize the vibration energy transmitted into a receiver and is especially useful because it is theoretically independent of the vehicle-side structure. While the blocked force methodology is not new, its application to beam axles is relatively unexplored in the literature. This paper demonstrates a case study of blocked force measurement of an electrified beam axle with a leaf spring suspension. The axle was tested
Shaw, Matthew DGrimmer, Michael J
The application of virtual point transformation for determining the transfer dynamic stiffness of a helical coil spring is demonstrated in this experimental study. Rigid fixtures are attached to both ends of the spring, and frequency response functions are measured using impact hammer excitations. These frequency response functions are transformed into virtual points, analogous to a node in finite element analysis, with six degrees of freedom. The six degrees of freedom transfer dynamic stiffness is then extracted using the inverse substructuring method, which eliminates the need to account for fixture dynamics. The results are validated by a direct measurement approach. Additionally, the study investigates the effect of liquid applied sprayed damping coatings on the spring's transfer dynamic stiffness, revealing that the coating significantly reduces vibration amplitudes at the surge frequencies. This suggest that the springs effective damping properties are enhanced.
Neihguk, DavidHerrin, D. W.de Klerk, Dennis
More and more captain-seat-like, luxury individual seats have been appeared inside MPV vehicles in order to meet various customer needs and improve market competitiveness. In the same time, customer complaints about seat vibration also increase significantly. Thus, luxury captain seat vibration is becoming MPV issues facing the vehicle development engineers. Typically, luxury captain seats are much heavier due to the added mechanisms to provide functions like massage or temperature controls, etc., and it is not feasible to structurally improve the seat modal frequencies to meet the need for NVH issue resolution. This paper presents a systematical study on the second-row luxury captain seat vibration issue between 10-25Hz with MPV vehicles. An axle contribution is analyzed with a 4-poster shaker test, and the test data show that the seat vibration is more sensitive to rear axle excitation than that of front axle, and to the out-of-phase excitation than the in-phase one. The similar
Zhou, ChangshuiYu Sr, JingGu, PerryZhang, FanBu, KunquanLiu, Xinhua
This article conducts a thorough review of contemporary air suspension systems on the market for passenger cars. The evolution of suspension structures and control methodologies are briefly discussed. The layout of air suspension systems is introduced in detail, with each component receiving a comprehensive description and analysis. The open-loop and closed-loop arrangements are explained. Various types of air springs are discussed and compared. The sensory system, special working conditions, and failure analysis are also elaborated. In the case studies, some example models are listed to show a complete guide of how air suspension is implemented on passenger cars, which includes functionalities, air spring configurations, control methods, signal flow, service modes, and diagnostic messages. The major sources are OEMs’ official websites and previously released documents, such as user manuals and maintenance manuals, which are valid up to April 2023. Finally, the article concludes with a
Ma, ChangyeLu, YukunZhen, RanLiu, YegangPan, BingweiKhajepour, Amir
Adverse weather conditions such as rain and snow, as well as heavy load transportation, can cause varying degrees of damage to road surfaces, and untimely road maintenance often results in potholes. Perception sensors equipped on intelligent vehicles can identify road surface conditions in advance, allowing each wheel’s suspension to actively adjust based on the road information. This paper presents an active suspension control strategy based on road preview information, utilizing a newly designed dual-chamber active air suspension system. It addresses the issue of point cloud stratification caused by vehicle body vibrations in onboard LiDAR data. The point cloud is processed through segmentation, filtering, and registration to extract real-time road roughness information, which serves as preview information for the suspension control system. The MPC algorithm is applied to actively adjust the nonlinear stiffness and damping of the suspension’s dual-chamber air springs, enhancing
Dong, FuxinShen, YanhuaWang, KaidiLiu, ZuyangQian, Shuo
This study examines a closed air spring suspension system. To address issues such as over-inflation, over-deflation, and excessive overshoot during vehicle height adjustment, a threshold control method is implemented. This method controls the triggering conditions for height adjustment and effectively reduces overshoot while enhancing precision. Experimental results indicate that this control strategy decreases overshoot and improves accuracy. However, risks are associated with varying threshold settings across different control modules, which can lead to over-control. A fuzzy PID controller is developed to resolve this issue. This controller adjusts PID parameters in real time based on fuzzy rules, thereby refining height adjustments. During testing, it was found that the degree of electromagnetic valve opening could not be controlled by the fuzzy PID controller. Therefore, a control strategy to adjust the compressor speed is designed. Experiments show that the fuzzy PID controller
Zheng, GuoqingYin, ZhihongChen, ShiwenShangguan, Wen-Bin
To investigate the static and dynamic mechanical properties of air springs and their influencing factors, two models were established in this paper to calculate the static and dynamic mechanical properties of air springs, including a simulation model based on the finite element method and a mathematical calculation model based on thermodynamic theory. First, a performance calculation model for rolling lobe air springs with aluminum tubes was established, which considered the thickness of the bellow and the impact of the inflation and assembly process on the state of the bellow. The static and dynamic mechanical properties of air springs were calculated using this model, including static load-bearing capacity and static/dynamic stiffness. The calculation results showed that both the static characteristics of the air spring under isothermal conditions and the dynamic characteristics under adiabatic conditions were able to be calculated accurately. However, the changes in dynamic
Wang, SiruiKang, YingziXia, ZhaoYu, ChaoLi, JianxiangShangguan, Wen-Bin
Taking a commercial vehicle cab suspension system as the research focus, a rigid-flexible coupled dynamics model was established based on the nonlinear characteristics of the integrated damper air spring and bushings. Time-domain vibration acceleration signals were acquired at the connection points between the frame, cab, and suspension. The vibration signals at the frame and suspension connection points were input into the simulation model, where the vibration responses at the cab and suspension connection points were calculated and analyzed using the established cab suspension system model. The accuracy of the model was verified by comparing the simulation results with experimental data. The established cab suspension system model was further used to evaluate human vibration comfort within the cab, following national standards for subjective human perception. A piecewise polynomial function was employed to fit the stiffness-damping characteristics of the integrated damper air spring
Hao, QiZhu, YuntaoSun, WenSun, KaiSun, ZhiyongHuang, YuZhen, RanShangguan, Wen-Bin
Traditional Hands-Off Detection (HOD) is realized by analyzing the torque applied to the steering wheel by the driver (driver torque), which is less accurate. In order to solve this problem, this paper takes the Column Electric Power Steering (CEPS) system as an object, analyzes the influence of the inertia effect and damping effect of the steering wheel and steering column on the HOD, establishes two kinds of state observers to obtain the accurate driver torque, proposes the estimation method of the road condition level, and can determine the torque threshold according to the information of the road condition level and the vehicle speed, and finally compares the driver torque and the torque threshold to obtain the HOD results. Experimentally, it is proved that this method can effectively reduce the interference of road surface interference on HOD. In addition, a fault-tolerant detection mechanism is proposed and validated to calculate the HOD result based on the frequency-domain
Huang, ZhaoLinLi, MinShangguan, WenbinDuan, XiaoChengXia, ZhiJun
The merging problem in the highway merge zone has been a research focus in the field of transportation for a long time. The rise of Connected and Automated Vehicles (CAVs) provides the potential to improve traffic flow efficiency, alleviate congestion and handle safety issues. However, existing two-dimensional merging strategies are facing challenges such as high computational complexity and the inevitable traffic oscillations during merging, which hinder the stability of traffic flow and fail to meet the dynamic requirements of merging control. To address these issues, this study proposes a distributed control strategy for CAVs in highway merge scenarios. Firstly, a virtual rotation method is designed to transform the merging problem of two different lanes into a car-following problem of a virtual platoon, and a virtual leader vehicle is introduced, to reduce computational complexity and determine vehicle sequencing. Based on this method, a Spring Cooperative Merging System (SCMS) is
Liu, YandanQu, Xu
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
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
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
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
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
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
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
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
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
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
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
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
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