Browse Topic: Finite element analysis

Items (3,283)
ABSTRACT BAE Systems has departed from traditional design rules of thumb and implemented a full-vehicle durability fatigue life analysis process at the design concept level to support lighter weight component designs. The durability process includes derivation of test duty cycles, generation of virtual loads from vehicle dynamic simulations, cascading of hundreds of channels of suspension attachment loads, and prediction of accumulated damage/fatigue life for both quasi-static and transient responses using a finite element vehicle structural model. The fatigue analysis process is typically deterministic, however the stochastic nature of the loads, material properties, and build variations should also be considered to ensure a robust durability process. The process is demonstrated on a heavy wheeled-vehicle platform using a generic duty cycle with examples shown at each stage of the process. This study additionally demonstrates the effects of variability of loads, materials, and
Purushothaman, NammalwarJayakumar, ParamsothyCritchley, JamesDatta, SandipPisipati, Venkat
ABSTRACT FBS Inc. is working with the TARDEC Electrified Armor Lab to develop a nondestructive structural health monitoring technology for composite armor panels that utilizes an array of embedded ultrasonic sensors for guided wave tomographic imaging. This technology would allow for periodic or real-time monitoring of armor integrity while being minimally intrusive and adding negligible weight. The technology is currently being developed and tested in pseudo composite armor panels and efforts are focused on reducing sensor array density, improving sensor integration procedures, and maximizing system sensitivity to damage. In addition to experimental testing and development, FBS is developing a highly-automated finite element model generation and analysis program to be used in conjunction with Abaqus/Explicit commercial finite element software. This program is specifically dedicated to modeling guided wave propagation in pseudo composite armor panels between embedded ultrasonic sensors
Borigo, Cody J.Bostron, JasonRose, Joseph L.Owens, Steven E.Reynolds, Thomas P.Meitzler, Thomas J.
ABSTRACT Researchers at Caterpillar have been using Finite Element Analysis or Method (FEA or FEM), Mesh Free Models (MFM) and Discrete Element Models (DEM) extensively to model different earthmoving operations. Multi-body dynamics models using both flexible and rigid body have been used to model the machine dynamics. The proper soil and machine models along with the operator model can be coupled to numerically model an earthmoving operation. The soil – machine interaction phenomenon has been a challenging matter for many researchers. Different approaches, such as FEA, MFM and DEM are available nowadays to model the dynamic soil behavior; each of these approaches has its own limitations and applications. To apply FEA, MFM or DEM for analyzing earthmoving operations the model must reproduce the mechanical behavior of the granular material. In practice this macro level mechanical behavior is not achieved by modeling the exact physics of the microfabric structure but rather by
Alsaleh, Mustafa
ABSTRACT Through Small Business Innovative Research (SBIR) support from the U.S. Army, an industry partner has explored the possibility of using an ultrasonic guided wave computed tomography (CT) imaging approach to detect and characterize ballistic damage to composite armor panels that are commonly used in ground vehicles. Laboratory tests have been conducted and shows that the guided wave CT approach can indeed be applied to these complex structures to provide accurate damage mapping potential. Analytical analysis and finite element method (FEM) modeling has been used to aide in understanding guided wave propagation behavior in these anisotropic structures. The work presented herein clearly shows great potential for using a guided wave sensing approach to locate and image ballistic damage in composite armor panels as well as the ability to predict wave propagation and scattering in these complex structures that could be used in the future to predict optimal sensor geometry
Royer, Roger L.Yan, FeiAvioli, Michael J.Meitzler, ThomasRose, Joseph L.Owens, Steven E.Bishnoi, Krishan
ABSTRACT Due to the severity of forces exerted during an IED blast, ground vehicles undergo multiple sub-events including local structural deformation of the floor, blast-off, free flight and slam-down (including rollover). Simulation of the entire blast event is computationally intensive due to the high fidelity level of the model and the long duration of the event. The purpose of this project was to develop a computationally-efficient, reduced order model to simulate the blast event in one single simulation, to be used for rapid evaluation of military ground vehicles. Models were developed using MADYMO’s rigid body and finite element integration techniques. Different methodologies used in MADYMO simulations, their performance results and comparisons are presented. A Hybrid III 50th Percentile male ATD model, enhanced for use in vertical loading conditions, was developed and validated to drop tower tests
Chandra, SherriRamalingam, JaisankarThyagarajan, Ravi
The integration of Artificial Intelligence (AI) and Machine Learning (ML) technologies has significantly changed various industries. This study demonstrates the application of a Convolutional Neural Network (CNN) model in Computational Fluid Dynamics (CFD) to predict the drag coefficient of a complete vehicle profile. We have developed a design advisor that uses a custom 3D CNN with a U-net architecture in the DEP MeshWorks environment to predict drag coefficients (Cd) based on car shapes. This model understands the relationship between car shapes and air drag coefficients calculated using computational fluid dynamics (CFD). The AI/ML-based design advisor feature has the potential to significantly decrease the time required for predicting drag coefficients by conducting CFD calculations. During the initial development phase, it will serve as an efficient tool for analyzing the correlation between multiple design proposals and aerodynamic drag forces within a short time frame
Bijjala, Sridhar
Leak Before Break (LBB) is now widely applied in pressure vessels and other pressurized components to detect the failure by unstable crack initiation and propagation. This concept is also applied in pneumatic brake system components to validate the structural rigidity of the devices. Pneumatic brake system component plays a vital role in the commercial vehicle platform. It consists of four major systems such as charging systems, actuating systems, control systems and actuators. Charging System includes compressor, reservoir, air dryer, and system protection valves. Compressor acts as an energy source for pneumatic air brake systems, reservoir is used to store the compressed air generated by the compressor, and system protection valves are used to divide and distribute the air flow to the brake system. Air dryers are used to absorb moisture, oil particles and tiny foreign contaminants, regulate the system pressure, and blow off the excess pressure from the system. It contains a
Govindarasu, AnbarasuT, SukumarSubramanian, Vivek
The functionality of the Powertrain mount is to securely anchor the engine and gearbox within a vehicle, and effectively absorb vibrations, while simultaneously shielding the vehicle's body from powertrain movements and road irregularities. The mounts are supported by engine mount brackets, which serve as connectors between the engine mount and the vehicle's body-in-white (BIW), providing a structural link that secures the engine and gearbox assembly. Conventionally made with materials such as aluminum, sheet metal, or cast iron, a recent surge has been seen toward using a viable substitute in Fiber Reinforced Polymer (FRP). This transition is driven by the potential to reduce weight and cost, while also improving Noise, Vibration, and Harshness (NVH) characteristics. This study aimed to evaluate the relative strengths of existing brackets compared to those made of FRP, with a focus on their modal response and crash resistance. Due to the absence of a standardized method for modelling
Hazra, SandipKhan, Arkadip
This paper investigates the structural integrity of a center console armrest structure for a four-wheeler automobile. The present analysis investigates to reduce the mass of the armrest structure without compromising the structural integrity of the armrest model. Various loading conditions are employed to study the effects on the structure. Finite element analysis (FEA) approach is utilized to study the effects of various loading conditions on the structure. Topology optimization technique is employed to reduce the mass. The design criteria followed to achieve the mass reduction are kept in check by considering the global von-mises stress criterion, designable and non-designable areas of the structure. Linear structural analysis is conducted with Multipoint constraint (MPC) contacts, 3D solid higher order tetrahedral and hexahedral elements and beam elements to perform the FEA analysis. Sequential Convex Programming (SCP) method is employed in topology optimization for performing the
Shah, VirenShekhar, RaviKushari, SubrataMiraje, JitendraD, Suresh
The primary purpose of the active safety feature is to reduce the danger of a collision between the car and an obstruction. To improve occupant safety, active safety systems must be included on all new vehicles; nonetheless, not all incidents are preventable. The frequency of incidents on the road has recently increased in tandem with the number of cars, making it critical to investigate the crashworthiness of a vehicle because human life is at the top of the priority list. This study examines an occupant's responses prior to a crash event, as well as studies into how occupant posture influences injury data. Most of the existing research focuses on the pre-crash event or the occupant's optimal seated position. However, it is critical to understand an occupant's reflex or behavior during the pre-crash event, when the occupant is typically not in an appropriate seating posture due to the panic reflex. As a result, an occupant's reflex in a panic situation will change their seating
Shankara Murthy, SantoshSrinivasa, PraveenCK, UmeshPatil, ShubhamJois, Rahul
Lift axle system is widely used in trucks and trailer to enhance the load carrying capacity by lowering the axle. Nowadays, this raising or lowering the axle is automated using electronic pressure switch. The Electronic pressure switch is used to sense the pneumatic pressure from Load Detection valve in Lift Axle control system and activates the solenoid valve which aids in filling the air in the lift bellows. The configuration used in this switch is Single Pole Double Throw (SPDT) which has 3 terminals such as 1 common contact,1 Normally open (NO) & 1 Normally closed (NC). The contact of the switch changes its state at forward switching pressure and returns to its normal state at the reverse switching pressure. During lab validation process, pressure leakage and diaphragm puncture is observed. Rubber diaphragm is one of the critical elements in this pressure switch which is used to avoid any leakage during the pressure transfer from the load detection valve. This rubber diaphragm is
K, Ganesh KumarGovindarasu, AnbarasuSankar, SweethaSundarrajan, Srinivasan
The aim of this work is to develop a composite material and investigate its mechanical characteristics especially suited for automotive applications, and finite element analysis (FEA) of fabricated composite is carried out to examine the mechanical behavior of composites. Utilizing aluminum alloy ingot (LM13) as the matrix material and zirconium diboride (ZrB2) as reinforcement, this work creates composites with improved mechanical and physical properties by accounting impact, tensile, compression, and hardness behavior. FEA is used to examine the increasing behavior of material properties for various volume segments of reinforcement (2.5, 5, 7.5, and 10 wt%) that are supplied to the matrix to determine an acceptable volume percentage of composite based on their input features. In FEA, the impact, tensile, compression, and hardness characteristics of the composite model are investigated by considering von Mises stress, equivalent elastic strain, and total deformation. The experimental
Vijayan, S. N.Chelladurai, Samson Jerold SamuelSaiyathibrahim, A.Infant Jegan Rakesh, A. J.Thriveni, K.Preethi, V.Jatti, Vijaykumar S.Karthik, S.Balaji, K.Saranya, S.
This study investigates the failure mechanisms of needle bearings within fuel transfer pump assemblies through a comprehensive approach combining endurance testing, detailed inspection, the Dykem blue method, proximity sensors, and finite element analysis (FEA). The findings reveal critical insights into the causes of failure, highlighting significant axial displacement, with a maximum of 0.37 mm measured by proximity sensors. The Dykem technique identified distinct wear patterns across various components, pinpointing areas of high stress and potential failure. Detailed bearing inspections uncovered trunnion damage and abrasive wear, corroborated by FEA, which quantified displacements of 0.144 mm in the x-direction, 0.030 mm in the y-direction, and 0.015 mm in the z-direction. The primary operational factors contributing to bearing failure were contamination and inadequate axial control. These insights are pivotal, as they align with and expand upon established literature on bearing
Kaliyanda, Aneesh
Arrays of radial cracks often appear at the bore of pressurized cylinders, posing potential safety risks and leading to possible structural failures. This article presents an analytical approach to evaluate the stress field arising from single or multiple uniform radial cracks in thick-walled pressurized cylinders within the context of linear elastic fracture mechanics (LEFM) under mode-I loading. This formulation is based on the fundamental equations of elasticity and approximations of stress intensity factors (SIF) reported in the literature. Hence, the SIF were revisited and their range of validity was highlighted. The study considers two types of internal pressure loading: one applied only to the cylinder’s inner surface with no pressure on the crack faces and another applied to both the inner surface and the crack faces. The influence of the number and length of cracks relative to cylinder thickness on the stress field is analyzed. A finite element model of the pressurized vessel
Methia, MounirBenslimane, AbdelhakimBechir, HocineAït Hocine, Nourredine
In light of global warming and power issues, reducing carbon emissions through the use of renewable energy sources has become a global concern. A ubiquitous mechanical motion in daily life is vibration, and one of the hot topics in this field of study is how to capture vibrational vitality and transform it to electrical power. Vibration dynamism can be captured by utilizing tribo-electric nano generators, which operate on the principles of electrostatic induction electrification due to contacts. COMSOL software is used to simulate the interaction between the voltage between the electrodes, the transferred charge, and the electrode moving distance of a triboelectric nanogenerator. A brief description of the simulation process is provided in this work, along with a theoretical interpretation of the simulation outcome. The experimental results revealed that increasing the rpm from 10 to 1000 per second led to substantial increase in Isc from 1.35nA to 225nA, cause enhanced triboelectric
P, GeethaJothiprashanth, R
Over the past few decades, there has been a notable increase in stakeholder’s attention on Earth's climate. The automotive industry, being a major contributor to this phenomenon, has been endeavoring to mitigate its impact through various measures. These efforts include reducing emissions in existing internal combustion engine (ICE) vehicles and promoting electric vehicles (EVs) as a feasible alternative for consumers. Despite these initiatives, there remains a persistent challenge in improving the fuel economy and driving range of vehicles. India, located along the Tropic of Cancer, experiences both tropical and subtropical climates. As a result, a substantial portion of the total heat absorbed is from solar radiation. The higher heat load necessitates extensive use of air conditioning (AC) systems, which significantly contributes to the overall power consumption of vehicles. Various measures are being implemented to mitigate this heat load and enhance the efficiency of AC operations
Kumar, SunnyVenu, SantoshRaj, ShivamKandekar, Ambadas
Due to its affordability and environmental friendliness, triboelectric nanogenerators, or TENGs, are a promising and alluring energy harvesting technology. Here, time-dependent finite-element numerical simulations were used to study the performance of dielectric-dielectric TENGs operating in the contact-separation mode. The open-circuit voltage, short-circuit current, and ideal resistance were measured in order to assess the TENG's performance. The findings are consistent with the physical models that are now available for the short-circuit current, which show that the current increases (decreases) with the area of the TENG (the thickness of the material). The open circuit voltage differed from published models according to the area and thickness of the material; the causes for this discrepancy are provided. Because high load resistance values affect charge flow in the TENG cycle (transient state) and performance, a deeper understanding of their effects is also offered. Here, the
P, GeethaSatyam, SatyamJothiprashanth, R
The continuously increasing demand for Battery Electric Vehicles, together with the customer requirement for higher ranges poses new challenges on the battery pack design. Drawing inspiration from aerospace design principles, wherein fuel tanks are integrated structurally into airframes to save weight and increase efficiency, structural battery packs are also experiencing growing use in the automotive field. In fact, when a structural battery pack is considered, significant weight savings can be achieved, potentially extending the vehicle range. Additionally, this weight saving could be further exploited to increase the battery pack size with respect to a non-structural battery pack, further enhancing the vehicle range without adding extra weight. To address the complexity of integrating structural battery packs, Finite Element simulations are typically adopted to evaluate battery pack integrity and estimate its contribution to the structural behaviour of the overall vehicle. However
Mangeruga, ValerioRenso, FabioSassetti, RiccardoGiacopini, Matteo
The current investigation delves into the thermal stresses encountered by internal combustion engine pistons during the combustion process and explores the impact of high heat transfer through metallic engine components. The study focuses on a thermal analysis of a diesel engine piston model, incorporating a semitransparent ceramic coating on its surface. The research simulates temperature profiles on both the top surface of the piston and its substrate. The model incorporates an internal heat source, its magnitude calculated based on the coating's heat radiation absorbance values. The investigation considers Aluminum, and Titanium ceramic-based coatings with varying heat flow duration. Comparative analysis involves assessing the results of the numerical solution of the heat equation, incorporating the internal heat source function derived from experimentally measured absorbance values of the coatings’ material. Unlike prior studies that primarily relied on evaluating temperature
Gutierrez, MarcosTaco, Diana
In this work, triaxial carbon fiber – epoxy composite laminates were manufactured and tested to determine the influence of environmental temperature and strain rate on the mechanical properties, and finite element models were developed to understand how those temperature and strain rate dependent trends may influence performance in a military ground vehicle application. As environmental temperature increased, the strength and elastic modulus were observed to decrease. Across all three environmental temperatures tested in this study, as the strain rate increased, tensile strength and elastic modulus were observed to increase as well. When applied to a composite hat section geometry, the finite element results highlighted the importance of considering both the environmental temperature and loading rate in the design of composite structures for use in military ground vehicles
Hart, Robert J.Patton, Evan G.Hamilton, Joseph M.Cardenas, IsabelaLuo, HuiyangMagallanes, Joseph
As engineering systems evolve to encompass more intricate and complex designs, featuring a broad range of physical phenomena, the task of modeling these systems with high fidelity becomes increasingly challenging. This complexity often surpasses what a single simulation tool can handle, requiring the integration of various tools to comprehensively cover all facets of the system, with their outcomes merged to represent the entire system accurately. This paper presents a case study of such an integration, focusing on a vehicle dynamics simulation that incorporates composite materials. The vehicle’s dynamics are modeled using Chrono, while the simulation of the composite materials is conducted in Abaqus. The outputs from both tools are then amalgamated to provide a complete description of the system
Montalbano, AndrewMocko, GregoryLi, Gang
The squeal noise is one of the critical factors to qualify a disc brake design from the Noise Vibration and Harshness (NVH) perspective. It is imperative to be watchful of the unstable natural modes of the brake assembly which trigger squeal. Any design modification for reducing a part’s contribution to targeted squeal mode can adversely affect and give rise to new squeal modes. Also, controlling conflicting requirements like mass, strength, and casting manufacturability, further adds up complexity, which increases design iterations and product cost. In view of these challenges, the application of the topological optimizations embedded under an artificial intelligence (AI) driven optimization workflow is explored. The scope of optimization is kept limited only to the caliper. Complex eigenvalue (EV) finite element analysis (FEA) of baseline design brake assembly is performed which predicts critical squeal mode having 34% strain energy contribution from caliper. To improve the squeal
Kumar, DineshInoue, HayuruYamamoto, MasayukiKhare, PrashantKasahara, TeruyasuHasegawa, Keita
Wheel bearings play a critical role in providing smooth rotation when vehicles move in straight line and turning motions. If a wheel bearing catastrophically fails, there is the possibility of vehicle damage or even personal injury. Since this is the case, wheel bearings require a higher level of reliability and robustness. With the drive towards a carbon neutral society against the background of global warming in recent years, the demand for lightweighting and lower friction for wheel bearings has become a priority. Weight reductions will cause larger deformation of each bearing component, and especially raceway deformation of the outer ring will impact bearing life. Therefore, optimization of the outer ring geometry is required to meet bearing life requirements and to achieve a lightweight design. In this research, we clarified not only the relationship between outer ring raceway deformation and multiple outer ring geometries under turning load using FEM (Finite Element Method) but
Kitada, TatsuyaSeki, MakotoImanaka, Hironori
Brake squeal is a phenomenon caused by various factors such as stiffness of brake components, mode coupling, friction coefficient, friction force variation, pressure, temperature and humidity. FEA simulation is effective at predicting and investigating the cause of brake squeal, and is widely used. However, in many FEA simulations, models of brake lining are mostly a brand-new shaper, so that the change of pressure distribution or pad shape, which can occur due to the lining wear, are not taken account. In this research, brake squeal analysis was conducted with consideration of lining wear, applying Fortran codes for Abaqus user subroutine. The brake assembly model for the analysis is created by using a 3D scanner and has a close shape to the real one. The wear patterns calculated by the analysis are similar to those of brake pads after a noise test. The complex eigenvalue analysis shows two unstable modes at the frequency of squeal occurred in the noise test. One is out-of-plane
Ikegami, TokunosukeMillsap, TomYamaguchi, Yoshiyuki
A method of overall modeling and step-by-step solution was proposed to verify and analyze the strength of the mount shell. First, a reliable finite element simulation model was established based on testing of the mechanical properties of rubber materials, constitutive model construction, and stiffness tests of the mounts. Second, the displacement of the mount system under preloading and crash loads was calculated separately through the modeling of the powertrain mount simulation, which provided accurate load conditions of the mount for the following work. Finally, the strength calculation and evaluation of the mount shell was completed with the quasi-static solution method. This calculation method could consider the influence of complex factors comprehensively, such as assembly load distribution, large deformation of rubber, and contact nonlinearity on the stress distribution of the mount shell. In addition, the calculation method could solve the problem of balance between solution
Li, KeliangChen, GuozhengSun, WanyuYan, ShanhengLi, MingLiu, Baoguo
This study aims to present a virtual numerical validation procedure for durability in brake system components, using artificial neural networks and based on experimental bench tests. The study focus was concentrated on the drum brake spider component, responsible for mechanically connecting the brake system subassemblies. To develop the validation procedure, engineering software such as ABAQUS, Fe-Safe, Minitab, and MATLAB was used. These were crucial for carrying out stress analyses, statistical data validation, and construction of an Artificial Neural Network (ANN) capable of predicting finite element responses, fatigue life, and supporting real-time decision-making for structural validation of mechanical components. The results obtained from these tools allowed the calibration of a numerical virtual model using the Finite Element Method (FEM) based on mechanical theories and results obtained in bench tests with the brake system, thus, a finite element database was generated for the
Marcon, LucasVieceli, AlexandreCorso, Leandro
Designing a brake disc is a very challenging job. Besides to being a key item in vehicle safety, we are referring to a product that goes through several manufacturing processes and during its application it is exposed to extreme conditions of mechanical stress, temperature and vibration. The raw material for a large portion of commercial brake discs is normally gray cast iron with the possibility of adding alloy elements. This material is characterized by having high resistance to wear due to friction and having practically zero plasticity. As it is a material without a plastic working regime, it is very important to properly size the product for use, once the material’s resistance limit is reached, a catastrophic failure in operation may be inevitable. Quality control systems in casting and machining have great importance in the development of the disc, but physical tests are always essential in this type of product. Dynamometer tests are great options for validating brake discs, due
Deckmann, Jardel Luisdo Nascimento, Vagner
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
Many sources and paths cause interior cabin noise. Some noise from an electric vehicle is unique and different from a vehicle with an internal combustion engine. Especially, whine noise occurs due to the particular orders of the electromagnetic force of an electric motor and transmission gears, which is tonal and usually reaches high frequencies. This paper covers structure-borne (SB) and airborne (AB) aspects to estimate whine, and the difference between the two characteristics is distinguished. The focus lies mainly on the process of virtual vehicle development and application for performance improvement. First, to predict SB whine, an e-powertrain is modeled as a finite element model (FEM), and electromagnetic (EM) forces are calculated. A vehicle model is also modeled as an FEM, in which interior sound packages are carefully modeled as they play an important role in the medium-frequency region. The e-powertrain and vehicle models (being simulated separately) are combined to obtain
Yoo, Ji WooChae, Ki-SangChoi, JaeHyukKim, MyunggyuCho, SeunghyeonCoster, ChristopheVan Gils, Anneleen
Society's growing environmental awareness and increasing urbanisation require new and innovative vehicle concepts. The use of additive manufacturing (AM) expands the design freedom in component development. In this paper, these are utilised to further develop a front axle suspension for a new type of modular vehicle concept. The wheel suspension components are optimised on the basis of a new method that has already been applied in previous work. This is based on industry-standard load cases for the strength design of the components, as well as the available installation space determined for the design of the suspension components and the suitable configuration of the suspension components. The component geometries identified using numerical methods that are suitable for the force flow are optimised with regard to the integration of information, energy and material-carrying lines in the control arms and the lines are used as load-bearing structures as extensively as possible. High
Weitz, FabianDebnar, ChristianFrey, MichaelGauterin, Frank
This study emphasizes the importance of CAE approach in optimizing EGR tube under vibrational load. EGR tube is a weak link in the EGR system and chances of failure due to vibration and relative displacement of mating parts, i.e., overhang or improper support at exhaust manifold, intake manifold, or EGR system. Consideration of the mating parts for the EGR tube is very important to get the realistic resonance frequencies, otherwise it could have some different results in the CAE, which will deviate from the reality. So, it’s important to study the dynamic response on the EGR tube, which needs to be taken care during the design phase. This paper aims to optimize the EGR tube under vibrational load by using CAE techniques and the industry experience as a product expertise. some critical parameter such as damping is very important during the CAE, which can be generated by doing the rigorous testing and how it affects the stress and correspondingly FOS. CAE model of EGR tube is created on
Munde, GaneshChattaraj, SandipHatkar, ChandanThakur, Abhishek Kumar
Although structural intensity was introduced in the 80’s, this concept never found practical applications, neither for numerical nor experimental approaches. Quickly, it has been pointed out that only the irrotational component of the intensity offers an easy interpretation of the dynamic behavior of structures by visualizing the vibration energy flow. This is especially valuable at mid and high frequency where the structure response understanding can be challenging. A new methodology is proposed in order to extract this irrotational intensity field from the Finite Element Model of assembled structures such as Bodies In White. This methodology is hybrid in the sense that it employs two distinct solvers: a dynamic solver to compute the structural dynamic response and a thermal solver to address a diffusion equation analogous to the thermal conduction built from the previous dynamic response. The field separation is based on the Helmholtz-Hodge theorem, which ensures the computation’s
Gagliardini, LaurentTakhchi, JamalSadoulet-reboul, EmelineOuisse, MorvanBornet, Frederic
Trim materials are often used for vibroacoustic energy absorption purposes within vehicles. To estimate the sound impact at a driver’s ear, the sub-structuring approach can be applied. Thus, transfer functions are calculated starting from the acoustic source to the car body, from the car body to the trim and, finally, from the trim to the inner cavity where the driver is located. One of the most challenging parts is the calculation of the transfer functions from the car body inner surface to the bottom trim surface. Commonly, freely laying mass-spring systems (trims) are simulated with a fixed or in some cases with a sliding boundary condition at the trim-structure interface. As a result, interface phenomena such as friction, stick-slip or discontinuities are not considered. Such approaches allow for faster simulations but result in simulations strongly overestimating the energy transfer, particularly in the frequency range where the mass-spring system’s resonances take place. In the
Bronzova, MariiaBocquillet, ArnaudSchanz, Martin
Tire/Road noise is a dominant contribution to a vehicle interior noise and requires significant engineering resources during vehicle development. A process has been developed to support automotive OEMs with road noise engineering during vehicle design and development which has test as its basis but takes advantage of simulation to virtually accelerate road noise improvement. The process uses noise sources measured on a single tire installed on a test stand in a chassis dynamometer. The measured sources are then combined with vehicle level transfer functions calculated using a Finite-Element model for structure-borne noise and a Statistical Energy Analysis (SEA) model for airborne noise to predict the total sound at the driver’s ears. The process can be applied from the initial stages of a vehicle development program and allows the evaluation of vehicle road noise performance as perceived by the driver long before the first prototype is available. This process is also extensible to
Hadjit, RabahWeilnau, KelbyEngels, BretMartin, SimonCalloni, MassimilianoMusser, Chad
Expansion chamber mufflers are commonly applied to reduce noise in heating, ventilation, and air-conditioning (HVAC) or exhaust systems. In dissipative mufflers, sound-absorptive materials, such as microperforated plates (MPP), are applied to achieve an enhanced and more broadband mitigation effect. Computational acoustics (CA) analyses of mufflers are usually carried out in the frequency domain, assuming time-harmonic excitation. However, certain applications require time-domain simulations. From a computational point of view, such transient analyses are more challenging. A transformation of the governing equations involving frequency-dependent material parameters into the time domain induces convolution integrals. We apply the recently proposed finite element (FE) formulation of a time-domain equivalent fluid (TDEF) model to simulate the transient response of dissipative acoustic media to arbitrary unsteady excitation. Like most time-domain approaches, the formulation relies on
Maurerlehner, PaulMayrhofer, DominikMehrgou, MehdiKaltenbacher, ManfredSchoder, Stefan
The structure-, fluid- and air-borne excitation generated by heating, ventilation and air conditioning (HVAC) compressors can lead to annoying noise and low frequency vibrations in the passenger compartment. These noise and vibration phenomena are of great interest to ensure a high passenger comfort of electric vehicles (EV). This publication describes the development of a numerical finite element (FE) model of the HVAC system and the simulation results of structure-borne sound transmission from the compressor via the HVAC hoses to the vehicle body in a frequency range up to 1 kHz. The simulation results were validated with measurements. An existing automotive HVAC system was fully replicated in the laboratory. Vibration levels were measured on the compressor and on the car body side of the hoses under different operational conditions. Additional measurements were carried out using external excitation of the compressor in order to distinguish between structure- and fluid-borne
Buchegger, BlasiusSonnberger, PiusBöhler, ElmarNijman, EugeneRejlek, JanBillermann, RobertKrüger, Yannik
Particle Dampers (PDs) are passive devices employed in vibration and noise control applications. They consist of a cavity filled with particles that, when fixed to a vibrating structure, dissipate vibrational energy through friction and collisions among the particles. These devices have been extensively documented in the literature and find widespread use in reducing vibrations in structural machinery components subjected to significant dynamic loads during operation. However, their application in reducing the vibration of vehicle body panels as well as vehicle interior noise has received, up to now, relatively little attention. Previous work by the authors [9] has proven the effectiveness of particle dampers in mitigating vibrations in vehicle body panels, achieving a notable reduction in structure-borne noise within the vehicle cabin with an additional weight comparable to or even lower than that of bituminous damping treatments traditionally used for this purpose. This effect may be
Sanchez Climent, Francisco VicenteBertolini, Claudio
To meet vehicle interior noise targets and expectations, components including those related to electric vehicles (EVs) can effectively be treated at the source with an encapsulation approach, preventing acoustic and vibration sources from propagating through multiple paths into the vehicle interior. Encapsulation can be especially useful when dealing with tonal noise sources in EVs which are common for electrical components. These treatments involve materials that block noise and vibration at its source but add weight and cost to vehicles – optimization and ensuring the material used is minimized but efficient in reducing noise everywhere where it is applied is critically important. Testing is important to confirm source levels and verify performance of some proposed configurations, but ideal encapsulation treatments are complex and cannot be efficiently achieved by trial-and-error testing. Simulation is a key supporting tool to guide location, thickness, and properties of
Van Hal, WillemGoy, OliverAmichi, KamelMusser, ChadwyckCalloni, MassimilianoHadjit, Rabah
With the increasing importance of electrified powertrains, electric motors and gear boxes become an important Noise Vibration & Harshness (NVH) source especially regarding whining noises in the high frequency range. Engine encapsulation noise treatments become often necessary and present some implementation, modeling as well as optimization issues due to complex environments with contact uncertainties, pass-throughs and critical uncovered areas. Relying purely on mass spring systems is often a too massive and relatively unefficient solution whenever the uncovered areas are dominant. Coverage is key and often a combination of hybrid backfoamed porous stiff shells with integral foams for highly complex shapes offer an optimized trade-off between acoustic performance, weight and costs. A dedicated experimental set-up has been designed in order to measure both structureborne and airborne NVH performances of engine encapsulation insulators applied on an engine casing placed in a coupled
Duval, ArnaudCrignon, GuillaumeGoret, Mickaellei, LeiWilkinson, AlexandreDauchez, NicolasPOLAC, Laurent
In vehicle Noise Vibration Harshness (NVH) development, vibroacoustic simulations with Finite Element (FE) Models are a common technique. The computational costs for these calculations are steadily rising due to more detailed modelling and higher frequency ranges. At the same time the need for multiple evaluations of the same model with different input parameters – e.g., for uncertainty quantification, optimization, or robustness investigation – is also increasing. Therefore, it is crucial to reduce the computational costs dramatically in these cases. A common technique is to use surrogate models that replace the computationally intensive FE model to perform repeated evaluations with varying parameters. Several different methods in this area are well established, but with the continuous advancements in the field of machine learning, interesting new methods like the Gaussian Process (GP) regression arises as a promising approach. In Gaussian Process regression there are important
Luegmair, MarinusDantas, RafaellaSchneider, FelixMüller, Gerhard
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