Display:

Results

2016-04-05
Journal Article
2016-01-0476
Yongchang Du, Yingping Lv, Yujian Wang, Pu Gao
Abstract Brake squeal is a complex dynamics instability issue for automobile industry. Closed-loop coupling model deals with brake squeal from a perspective of structural instability. Friction characteristics between pads and disc rotor play important roles. In this paper, a closed-loop coupling model which incorporates negative friction-velocity slope is presented. Different from other existing models where the interface nodes are coupled through assumed springs, they are connected directly in the presented model. Negative friction slope is taken into account. Relationship between nodes’ frictional forces, relative speeds and brake pressure under equilibrant sliding and vibrating states is analysed. Then repeated nodal coordinate elimination and substructures’ modal coordinate space transformation of system dynamic equation are performed. It shows that the negative friction slope leads to negative damping items in dynamic equation of system.
2016-04-05
Journal Article
2016-01-0477
Pu Gao, Yongchang Du, Yujian Wang, Yingping Lv
Abstract The dynamic properties of disc rotor play important role in the NVH performance of a disc brake system. Disc rotor in general is a centrosymmetric structure. It has many repeated-root modes within the interested frequency range and they may have significant influence on squeal occurrence. A pair of repeated-root modes is in nature one vibration mode. However, in current complex eigenvalue analysis model and relevant analysis methods, repeated-root modes are processed separately. This may lead to contradictory result. This paper presents methods to deal with repeated-root modes in substructure modal composition (SMC) analysis to avoid the contradiction. Through curve-fitting technique, the modal shape coefficients of repeated-root modes are expressed in an identical formula. This formula is used in SMC analysis to obtain an integrated SMC value to represent the total influence of two repeated-root modes.
2016-04-05
Technical Paper
2016-01-0518
Choonsoo Han
Abstract Thermoplastic polyester elastomer (TPEE) has the properties of both rubber and engineering plastic. The most important characteristics of this material are its high elasticity and rigidity. So, those properties are enable to high durability against fatigue and large deformation cycles. In this study, the rebound bumper of suspension system in vehicle, using thermoplastic polyester elastomer was conducted. The plastic elastomer rebound bumper allows cost reduction and light weight on by integrating several components, such as coil spring, spring guides, blocker, stop rubber etc. In order to satisfy several component requirements such as specific compression set and Load-Displacement curve etc, we evaluated the performance change according to the design and material of the component. This study shows that how to modify the design of the rebound bumper to meet the requirments, and to choose the optimum material through the verification comparing several materials.
2016-04-05
Technical Paper
2016-01-0508
Hyung Seok KIM
Abstract This study provides a tire puncture sealant including NR latex and acrylic emersion, which has a reduced viscosity at -40°C, and is also excellent storage stability at -40°C to 70°C, initial sealing performance. Also, this study provides device for sealing inflatable objects. 'One- Piece Tire Repair Kit' can reduce weight and operation steps.
2016-04-05
Technical Paper
2016-01-0507
Kazunori Miyake, Tomoya Nishida, Takanori Kurokawa, Hirokazu Arai
Abstract Sliding intermediate shaft of Electric Power Steering (EPS) system is used for torque transmission from steering wheel or motor and buffering reverse input from tire. Polyamide coating material with good sliding properties is treated in the sliding types of intermediate shaft. Conventionally, sliding types of intermediate shaft with polyamide coating have been used in vehicle interior. On the other hand, extension of applied area to engine room is needed. However, in high temperature conditions, there is concerns about increase of friction coefficient and wear volume of polyamide by deterioration of sliding properties of polyamide. Therefore, improvement of sliding properties of polyamide in high temperature is necessary. In this research, we examined sliding properties of polyamide blended with metal stearate in high-temperature to use polyamide in high temperature compared to conventional environment. As resin material, we used polyamide 610 blended with metal stearates.
2016-04-05
Technical Paper
2016-01-1327
Zhenfeng Wang, Mingming Dong, Junfeng Xiang, Pu Gao, Liang Gu, Yushuai Wang
Abstract The study of mechanical properties special in the characteristics of elastic element is a challenging task for vehicle industry. Since torsion bar spring acts as an important part of elastic element, and improves performance of torsion bar spring is of great concern. The effects of the torsion bar spring pre-setting precision on the presetting performance are presented. Based on elastic-plastic theories, the algebraic model of torsion bar spring is established to analyze the stress, torque and residual stress under the yield and plastic conditions in pre-setting process. Then, the stress and strain states of various torsion bar springs in different conditions are simulated using the validated finite element model in ABAQUS software. The simulation results show the effects of torsion error on the pre-setting performance are less than 5% in the pre-setting process.
2016-04-05
Journal Article
2016-01-1569
Kiho Yum
Abstract In this research, the influence of tire force and moment (F&M) characteristics on vehicle on-center steering performance was analyzed and then how to improve vehicle on-center performance was studied through controlling tire structure design parameter, tread pattern shape and tread grip characteristics. First, the relationship between vehicle on-center steering performance and tire F&M characteristics was identified by comparing vehicle steering measurements and tire F&M measurements. It was found that key factor of tire related with on-center performance is aligning torque at lower slip angles. As the aligning torque at slip angle 1° increases, on-center feel is improved. Second, the influence of tire design parameters on tire aligning torque was studied through F&M finite element (FE) analysis and measurement. It was found that the aligning torque at lower slip angle increases as stiffness of the tread and sidewall decreases.
2016-04-05
Technical Paper
2016-01-1546
Dongpil Lee, Bongchoon Jang, Kyongsu Yi, Sehyun Chang, Byungrim Lee
Abstract This paper describes a reference steering feel tracking algorithm for Electric-Power-Steering (EPS) system. Development of the EPS system with intended steering feel has been time-consuming procedure, because the feedforward map-based method has been applied to the conventional EPS system. However, in this study, a three-dimensional reference steering feel surface, which is determined from current vehicle states, is proposed. In order to track the proposed reference steering feel surface, sliding mode approach is applied to second-order steering dynamics model considering a coulomb friction model. An adaptive technique is utilized for robustness against uncertainties. In order to validate the proposed EPS control algorithm, hardware-in-the-loop simulation (HILS) has been conducted with respect to a typical steering test. It is shown that the reference steering feel is realized well by the proposed EPS control algorithm.
2016-04-05
Technical Paper
2016-01-1559
Francesco Vinattieri, Tim Wright, Renzo Capitani, Claudio Annicchiarico, Giacomo Danisi
Abstract The adoption of Electrical Power Steering (EPS) systems has greatly opened up the possibilities to control the steering wheel torque, which is a critical parameter in the subjective and objective evaluation of a new vehicle. Therefore, the tuning of the EPS controller is not only becoming increasing complicated, containing dozens of parameters and maps, but it is crucial in defining the basic DNA of the steering feeling characteristics. The largely subjective nature of the steering feeling assessment means that EPS tuning consists primarily of subjective tests on running prototypes. On account of that, this paper presents an alternative test bench for steering feeling simulation and evaluation. It combines a static driving simulator with a physical EPS assisted steering rack. The end goal is to more accurately reproduce the tactile feedback to the driver by including a physical hardware in lieu of complicated and difficult to obtain software models.
2016-04-05
Technical Paper
2016-01-1544
Dexin Wang, Frank Esser
Abstract Evaluation of electric steering (EPAS) system performance using vehicle specific load conditions is important for steering system design validation and vehicle steering performance tuning. Using real-time vehicle dynamics mathematical models is one approach for generating steering loads in steering hardware-in-the-loop (HIL) testing. However achieving a good correlation of simplified mathematical models with real vehicle dynamics is a challenge. Using rack force models from measured steering tie rod forces or from simulations using a high-fidelity vehicle dynamics model is an effective data-driven modelling method for testing EPAS systems under vehicle specific load conditions. Rack force models are identified from physical measurements or validated vehicle simulations of selected steering test maneuvers. The rack force models have been applied in steering system performance evaluation, benchmarking, and steering model validation.
2016-04-05
Technical Paper
2016-01-1627
Liangxiu Zhang, Guangqiang Wu
Abstract In order to improve the robustness and stability of autonomous vehicle at high speed, a path tracking approach which combines front steering and differential braking is investigated in this paper. A bicycle model with 3-DOFs is established and a linear time-varying predictive model using front steering as its control input can be derived. Based on model predictive theory, the path tracking issue using linear time-varying model predictive control can be transformed into an online quadratic programming problem with constraints. The expected front steering angle can be obtained from online moving optimization. Then the direct yawing control is adopted to treat two types of differential braking control. The first one investigates steady-state gain of yaw rate in linear 2-DOFs vehicle model, and designs a stable differential braking controller which is based on reference yaw rate.
2016-04-05
Journal Article
2016-01-1175
Ran Bao, Richard Stobart
Abstract A control strategy has been designed for a city bus equipped with a pneumatic hybrid propulsion system. The control system design is based on the precise management of energy flows during both energy storage and regeneration. Energy recovered from the braking process is stored in the form of compressed air that is redeployed for engine start and to supplement the engine air supply during vehicle acceleration. Operation modes are changed dynamically and the energy distribution is controlled to realize three principal functions: Stop-Start, Boost and Regenerative Braking. A forward facing simulation model facilitates an analysis of the vehicle dynamic performance, engine transient response, fuel economy and energy usage.
2016-04-05
Technical Paper
2016-01-0445
Brian Paul Wiegand
Abstract Evaluation of the performance potential of an automotive conceptual design requires some initial quantitative estimate of numerous relevant parameters. Such parameters include the vehicle mass properties, frontal and plan areas, aero drag and lift coefficients, available horsepower and torque, and various tire characteristics such as the rolling resistance coefficient(s)… A number of rolling resistance models have been advanced since Robert William Thomson first patented the pneumatic rubber tire in 1845, most of them developed in the twentieth century. Most early models only crudely approximate tire rolling resistance behavior over a limited range of operation, while the latest models overcome those limitations but often at the expense of extreme complexity requiring significant computer resources.
2016-04-05
Journal Article
2016-01-1645
Carlo Lugaro, Antoine Schmeitz, Toshiya Ogawa, Tetsuya Murakami, Sonny Huisman
Abstract A vehicle parking manoeuvre is characterized by low or zero speed, small turning radius and large yaw velocity of the steered wheels. To predict the forces and moments generated by a wheel under these conditions, the Pacejka Magic Formula model has been extended to incorporate the effect of spin (turn slip model) in the past years. The extensions have been further developed and incorporated in the MFTyre/MF-Swift 6.2 model. This paper describes the development of a method for the identification of the turn slip parameters. Based on the operating conditions of a typical parking manoeuvre, the dominant parameters of the turn slip model are firstly defined. At an indoor test facility, the response of a tyre under the identified operating conditions is measured. An algorithm is developed to identify the dominant turn slip parameters from the measured responses.
2016-04-01
Standard
J511_201604
This pneumatic spring terminology has been developed to assist engineers and designers in the preparation of specifications and descriptive material relating to pneumatic springs and their components. It does not include gas supply or control systems.
2016-04-01
Standard
J2800_201604
This lab test procedure should be used when evaluating the combined corrosion and fatigue performance for a particular coating system, substrate, process and design. The test is intended to provide an A to B comparison of a proposed coil spring design versus an existing field validated coil spring when subjected to the combined effects of corrosion and fatigue. The corrosion mechanisms covered by this test include general, cosmetic and pitting corrosion. Fatigue testing covers the maximum design stress and/or stress range of the coil spring design (typically defined as excursion from jounce to rebound positions in a vehicle). The effects of gravel and heat are simulated by pre-conditioning the springs prior to fatigue testing. Time dependant corrosion mechanisms such as stress corrosion cracking are not addressed with this test.
2016-03-30
WIP Standard
J2194
Any ROPS meeting the performance requirement of ISO 5700 (Static ROPS Test Standard) or ISO 3463 (Dynamic ROPS Test Standard) meets the performance requirements of this SAE Standard if the ROPS temperature/material and seat belt requirements of this document are also met. Fulfillment of the intended purpose requires testing as follows: A temperature-material requirement (6.9). This can be satisfied by using the appropriate materials or by performing any of the structural performance tests (Sections 7, 8, or 9) at -18 °C. A laboratory test, under repeatable and controlled loading, to permit analysis of the ROPS for compliance with the performance requirements of this document. Either the static test sequence (Section 7) or the impact test sequence (Section 8 ) shall be conducted. See Figure 1. A seat belt anchorage test (Section 10). The test procedures and performance requirements outlined in this document are based on currently available engineering data.
2016-03-30
WIP Standard
J1194
Fulfillment of the intended purpose requires testing as follows: A laboratory test, under repeatable and controlled loading, to permit analysis of the ROPS for compliance with the performance requirements of this SAE Standard. Either the static test (6.1) or the dynamic test (6.2) shall be conducted. A crush test to verify the effectiveness of the deformed ROPS in supporting the tractor in an upset attitude. A field upset test under reasonably controlled conditions, both to the rear and side, to verify the effectiveness of the protective system under actual dynamic conditions. (See 6.4.1.1 for requirements for the omission of this test). In addition to the laboratory and field loading requirements, there is a temperature-material requirement. (See 7.1.2.) The test procedures and performance requirements outlined in this document are based on currently available engineering data.
2016-03-29
WIP Standard
J1337
This SAE Information Report covers the important fundamental maintenance and service precautions for all off-road single-piece and multi-piece rims. Detailed information on specific procedures concerning mounting, demounting, maintenance and service of a particular type, style, or design of off-road rim assembly can be obtained by consulting rim or tire manufacturers or distributors. These procedures and service precautions are guidelines to be considered in preparation of the machine service manual and operator's manual and workplace procedures. It is the intent of this Information Report to allow for further development and review of these guidelines and then make this document a Recommended Practice.
2016-03-27
Technical Paper
2016-01-1710
Ek-u thammakornbunjut, Sutee Olarnrithinun
In general, the automotive chassis will be subjected to a combination of dynamic loads. The important one of these loads is an impact load which will be occurred when a vehicle crash to another vehicle or infrastructures. This paper aims to investigate the axial impact strength of a C-shape straight beam reinforced with dented rectangular plates. Only spherical shape of the dent is considered in this study. The effects of dent diameter, dent depth, and number of dented plates are analyzed using nonlinear finite element method. The possibility to use this type of reinforcement is discussed.
2016-03-25
WIP Standard
J712
The purpose of this SAE Recommended Practice is to provide a selection of disc wheels for industrial and agricultural application with a maximum of interchangeability. This is accomplished by establishing five groups of disc wheels, in each of which the hub mounting elements are common. These groups are designated 4 bolt, 5 in bolt circle; 5 bolt, 4.5 in bolt circle; 5 bolt, 5.5 in bolt circle; 6 bolt, 6 in bolt circle; and 8 bolt, 8 in bolt circle. Further, this document establishes an SAE part number and the maximum rated radial load for each standard wheel. In addition, the document requires the wheel manufacturer's name or trademark to be impression stamped on the wheel with location at the discretion of the manufacturer.
2016-03-23
Standard
J175_201603
The SAE Recommended Practice establishes minimum performance requirements and related uniform laboratory test procedures for evaluating lateral (curb) impact collision resistance of all wheels intended for use on passenger cars and light trucks.
2016-03-18
Standard
J1986_201603
This SAE Recommended Practice is intended to serve as a guide for standardization of features, dimensions, and configurations of balance weights for aluminum and steel wheels intended for use on passenger cars, light trucks, and multipurpose vehicles to assure good installation and retention of the balance weight. This document also provides test procedures and minimum performance requirements for testing balance weight retention.
2016-03-18
Standard
J328_201603
This SAE Recommended Practice provides minimum performance requirements and uniform procedures for fatigue testing of wheels intended for normal highway use and temporary use on passenger cars, light trucks, and multipurpose vehicles. For heavy truck wheels and wheels intended to be used as duals, see SAE J267. For wheels used on trailers drawn by passenger cars, light trucks, or multipurpose vehicles, see SAE J1204. These minimum performance requirements apply only to wheels made of materials included in Tables 1 to 4. The minimum cycles noted in Tables 1 through 4 are to be used on individual test and a sample of tests conducted, with Weibull Statistics using 2 parameter, median ranks, 50% confidence level and 90% reliability, typically noted as B10C50.
2016-03-17
WIP Standard
ARP6412
The scope of the Landing Gear Integrity Programs (LGIP) Aerospace Recommended Practice (ARP) is intended to assist in the safe-life structural integrity management of the landing gear system and subsystems components. In addition, component reliability, availability, and maintainability is included in a holistic LGIP.
2016-03-16
Standard
AIR5656A
This SAE Aerospace Information Report (AIR) provides a methodology for performing a statistical assessment of gasturbine- engine stability-margin usage. Consideration is given to vehicle usage, fleet size, and environment to provide insight into the probability of encountering an in-service engine stall event. Current industry practices, such as ARP1420, supplemented by AIR1419, and engine thermodynamic models, are used to determine and quantify the contribution of individual stability threats. The statistical technique adopted by the S-16 committee for performing a statistical stability assessment is the Monte Carlo method (see Applicable References 1 and 2). While other techniques may be suitable, their application is beyond the scope of this document. The intent of the document is to present a methodology and process to construct a statistical-stability-assessment model for use on a specific system and its mission or application.
2016-03-16
Standard
AS6296
This SAE Aerospace Standard (AS) specifies minimum performance standards for Electronic Flight Information System (EFIS) displays that are head-down and intended for use in the flight deck by the flight crew in all 14 CFR Part 23, 25, 27, and 29 aircraft. This document is expected to be used by multiple regulatory agencies as the basic requirement for a technical standard order for EFIS displays.
2016-03-15
Article
Cadillac has aggressively used light materials for its recently-launched new cars, but for the all-new C1 architecture underpinning the XT5 crossover, engineers stuck with steel—and still achieved a major weight reduction.
2016-03-15
Standard
J1817_201603
This SAE Recommended Practice describes a marking system to distinguish long-stroke from standard stroke for service, parking, and combination air-brake actuators, roto-chambers, and components. Said actuators are used for applying cam and disc-type foundation brakes by slack adjuster means.
2016-03-15
WIP Standard
AIR6411
Provide information and guidance for landing gear operation in cold temperature environment. Covers all operational aspects on ground and in flight. Includes effects on: tires, wheels, brakes, shock strut, seals, and actuation.

Filter