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Viewing 91 to 120 of 10886
2017-03-28
Journal Article
2017-01-0411
Yuming Yin, Subhash Rakheja, Jue Yang, P-E. Boileau
Abstract This study is aimed at characterizing the nonlinear stiffness and damping properties of a simple and low cost design of a hydro-pneumatic suspension (HPS) that permits entrapment of gas into the hydraulic fluid. The mixing of gas into the oil yields highly complex variations in the bulk modulus, density and viscosity of the hydraulic fluid, and the effective gas pressure, which are generally neglected. The pseudo-static and dynamic properties of the HPS strut were investigated experimentally and analytically. Laboratory tests were conducted to measure responses in terms of total force and fluid pressures within each chamber under harmonic excitations and nearly steady temperature. The measured data revealed gradual entrapment of gas in the hydraulic fluid until the mean pressure saturated at about 84% of the initial pressure, suggesting considerably reduced effective bulk modulus and density of the hydraulic fluid.
2017-03-28
Journal Article
2017-01-0419
Yuliang Yang, Yu Yang, Ying Sun, Jian Zeng, Yunquan Zhang
Abstract In addition to ride comfort, handling stability and other conventional vehicle performances, we should also focus on other aspects of performance to a center axle trailer combination, such as the maximum stable side-inclination, the anti-rolling stability, the lateral stability and so on. Based on the finite element method, a rigid-flexible coupling model for the truck combination was built and analyzed in the multi-body environment (ADAMS), in which the key components of the chassis and cab suspension were treated as flexible bodies. A series of simulations were carried out to evaluate the lateral stability of the center axle trailer in accordance with the relevant regulations of the vehicle. The influence of design variables on the lateral stability was studied by an experiment. Furthermore, in order to improve the lateral stability of the trailer combination, the optimal design was obtained by the co-simulation of the ADAMS/Car, iSIGHT and Matlab.
2017-03-28
Technical Paper
2017-01-1058
L.V. Pavan Kumar Maddula, Ibrahim Awara
Abstract Increased focus on fuel efficiency and vehicle emissions has led the automotive industry to look into low weight alternative designs for powertrain system components. These new design changes pose challenges to vehicle attributes like NVH, durability, etc. Further, the requirement of high power applications produces even more complexities. The present work explains how a potential design change of half shafts driven by a desire to reduce weight and cost can lead to NVH problems caused by half shaft resonances and explains how using multiple dynamic vibration absorbers can solve the issue to meet customer expectation while improving efficiency. With the aid of Finite Element Analysis (FEA) & optimization software, interactions between multiple DVA’s on a system was understood and optimal damper parameters for effective damping was identified. The final DVA design was tested and verified on the vehicle for optimal attribute performance.
2017-02-13
WIP Standard
J2789
This Recommended Practice is useful to determine the inertia value (wheel load and tire radius) using three basic methods (fixed brake work split, dynamic weight transfer, and axle rating) to determine the wheel load and two methods to determine the tire radius (SLR and rolling radius). The inertia values are required to determine the amount of energy and brake work imposed on the brake during testing. The inertia level (mechanical or simulated) is required also to calculate deceleration levels from a given torque value or the torque level for a given deceleration value or set-point. This procedure is applicable to all passenger cars and light trucks up to 4,540kg of GVWR.
CURRENT
2017-02-13
Standard
J2611_201702
This SAE information report covers the basic guidelines concerning off-road tire conditions that warrant replacement, removal, or repair. This material can assist the tire user in establishing specific written procedures for each job site.
2017-02-10
WIP Standard
J2899
This SAE Recommended Practice applies to S-CAM, Wedge, and Disc air brake actuators where the stroke can be measured without disassembly from the brake.
2017-02-09
Article
UQM Technologies signed a development agreement with Meritor to jointly develop E-axles for the medium- and heavy-duty EV commercial market, according to a February 2 announcement. Prototypes are expected by early fall of 2017.
2017-02-09
WIP Standard
J2247
This SAE Recommended Practice identifies the minimum truck tractor electrical power output of the stop lamp and ABS (antilock brake system) circuits measured at the primary SAE J560 tractor trailer interface connector(s).
CURRENT
2017-02-09
Standard
J1469_201702
This SAE Recommended Practice provides procedures and methods for testing service, spring applied parking, and combination brake actuators with respect to durability, function, and environmental performance. A minimum of six test units designated A, B, C, D, E, and F are to be used to perform all tests per 1.1 and 1.2.
2017-02-02
Magazine
The next phase Meeting Phase 2 fuel efficiency and GHG emissions for heavy trucks will require multiple technology pathways—some of which are still on the horizon. Active vibration damping for construction machines An innovative concept for an active system to reduce machine oscillations based on frequency identification. Consumer electronics come on board Smartphones and tablets are likely to play a large role in HMIs for heavy vehicles—if productivity and safety are not compromised. Patton’s new campaign As new SAE International President for 2017, Doug Patton will advocate STEM, “cultivation” of prospective young engineers. PACCAR’s Sproull primed for SAE Commercial Vehicle post As SAE International’s new 2017-2020 Commercial Vehicle Sector VP, Landon Sproull intends to bolster the society’s involvement in evolving industry regulations and to better cultivate cross-sector alliances.
CURRENT
2017-02-02
Standard
J2581_201702
This SAE Information report defines the thermal transport properties important in the assessment of heat management capability of brake lining, shoe, disc and drum materials. The report discusses thermal diffusivity, specific heat capacity, thermal conductivity and thermal expansion. Measurement techniques for the appropriate ASTM standards are identified. The thermal transport properties discussed are material sample properties, not the properties of entire components such as pad assemblies.
CURRENT
2017-02-02
Standard
J379_201702
Hardness measurements are used as a quality control check of the consistency of formulation and processing of brake linings. Gogan hardness is nondestructive (the penetrator causes shallow surface deformation.). Gogan hardness method alone does not show anything about a lining’s ability to develop friction or to resist fade when used as a friction element in brakes. The hardness and the range of hardness are peculiar to each formulation, thickness, and contour; therefore, the acceptable values and ranges must be established for each formulation and part configuration by the manufacturer.
CURRENT
2017-02-02
Standard
J380_201702
Specific gravity is a nondestructive test used as a quality control check of the consistency of formulation and processing of brake lining. The specific gravity and the range of specific gravity are peculiar to each formulation and, therefore, the acceptable values or range must be established for each formulation by the manufacturer. Specific gravity alone shows nothing about a materials in use performance. The specific gravity of sintered metal powder friction materials, particularly those which have steel backing members, is usually determined somewhat differently. Reference ASTM B 376. Purpose To establish a uniform procedure for determining the specific gravity of brake friction material.
2017-01-31
WIP Standard
AIR6417
This Aerospace Information Report (AIR) provides information related to experience with carbon brake quality-assurance rejected takeoff tests, and considerations regarding test setup, test conditions, test frequency and cost considerations.
2017-01-25
Article
Dr. Christian Wiehen, Chief Technology Officer for WABCO, discusses ADAS, platooning and automated future for trucks.
2017-01-23
Article
Volvo Construction Equipment offers increased payload capacities among other features on the new A45G articulated hauler.
CURRENT
2017-01-12
Standard
ARP5429A
This SAE Aerospace Recommended Practice (ARP) applies to fatigue testing of landing gear and landing gear components.
2017-01-10
Technical Paper
2017-26-0220
Ashutosh Dubey, Palish Raja, Nitin Chopra, Ashok Patidar, Manu Kaushik
Abstract With the increase in the sensitivity of power steering system in the competitive environment, it becomes essential to provide a trouble free steering system to the customer. Usually major concerns faced in the performance of steering system are related to noise like vane pump whining noise and steering gearbox erratic rubbing noise. Even though selected steering pump and reservoir are quite compatible to the steering gearbox. With the series of Computational Fluid Dynamics (CFD) simulations and field tests, it is found that the cavitation phenomena in steering oil routing lines is responsible for the steering turning noise. In this paper, a developed systematic approach for problem detection to implementation of design solution is discussed.
2017-01-10
Technical Paper
2017-26-0218
Chaitanya Chilbule, S B Phadke, R N Kulkarni, M P Raajha
Abstract As an automobile brake manufacturer, brake noise always been a prime concern as it define the degree of customer satisfaction and warranty claim. Brake squeal is a concern in the automotive industry that has challenged many researchers and engineers for years. In case of disc brake, brake-squeal (1 to 16 kHz) occurrence is predominant than the any other types of brake-noise (i.e. moan, grown, judder etc.), since squeal is a friction induced, self-excited, and self-sustained phenomenon from a nonlinear dynamics viewpoint. Due to the complexities involve squeal mechanism is not well understood yet, hence makes it one of the unresolved brake Noise, Vibration, and Harshness (NVH) problem till this date. Since squeal is a high-pitched and tonal noise, therefore it is very annoying and getting more attention by occupants. Brake squeal can occur at any temperature and with or without the presence of humid condition and therefore highly unpredictable.
2017-01-10
Technical Paper
2017-26-0261
Ashesh Anil Shah, Ashok Patidar
Abstract Paper explains conversion of existing drum brake system to disc brake system with complete digital validation at structural as well as thermal level to make sure First Time Right Design before physical part development. To provide leverage to quick design, modification and selection of brake system according to vehicle configuration, a virtual computational fluid dynamics (CFD) simulation process is developed and validated with test results. Temperature variation over brake drum and disc in internal standard braking cycle is measured virtually and correlated with test results. Also Fade testing criteria’s were considered during CFD analysis. This up gradation is must considering technology enhancement trend and safety in automotive segment. In current competitive market scenario and as per customer requirements, front disc brake module is becoming necessary not only for passenger segment but also for commercial segment vehicle.
2017-01-10
Technical Paper
2017-26-0259
Sandeep V. Sawangikar, Jeevan N. Patil, Sivakumar Palanivelu, Arun Kumar K
Abstract Steering system deliver a precise directional control to the vehicle chassis and ensure the safe driving at all maneuvers. Hydraulic power assisted system (HPAS) helps drivers to steer by boosting steering assistance of the steering wheel while retaining the road feel. HPAS performance is associated with the design characteristics of rotary valve, steering, suspension, kinematics, brake, tire, vehicle speed and load transfer. Thus a detailed power steering system model is absolutely necessary to evaluate and optimize the performance characteristics. However, many components of HPAS system are proprietary in nature so it is very challenging to get component characteristic of each sub-system for the complete power steering system model. Hence, it is very important to establish a technique to extract all such influencing characteristics with available test facility.
2017-01-10
Technical Paper
2017-26-0246
Srinivas Kurna, Ruchik Tank
Abstract The job of a suspension system is to maximize the friction between the tires and the road surface, to provide steering stability with good handling and to act as a cushioning device to ensure the comfort of the driver and passengers. The suspension system also protects the vehicle and any cargo or luggage from damage and wear. Commonly the strength of these suspension systems is evaluated by endurance trials on field or Rig testing which are time consuming and costly. On the other hand, virtual testing methods for strength and stiffness evaluation provide useful information early in the design cycle and save significant time and cost. However, the virtual method also needs validation, which can be achieved by physical co-relations (via rig tests). A study has been done to predict the behavior of Leaf Spring Suspensions entirely through the FEA (Finite Element Analysis) route and correlating those results with physical test.
2017-01-10
Technical Paper
2017-26-0080
P. Ramani Ranjan Senapati, Soumyo Das, Prashantkumar B. Vora
Abstract The development of intelligent driver assistance mechanism ensures safety and comfort of passengers, the intelligent braking and maneuvering mechanism is proposed by transforming the anti-lock braking technology for a four wheeled vehicle. This paper presents an active safety mechanism which incorporates both steering and braking assistance system in a maneuvering vehicle. The algorithm of collision avoidance mechanism is featured and interfaced in an intelligent vehicle with short range radar to assist driving system of host vehicle based on predicted motion of sensed obstacles. The developed system will be activated for obstacles in front of the host vehicle within critical risk level. The intelligent braking mechanism plays a pivotal role at the time of emergency situation depending on the predicted collision time and relative velocity between host and target, it also provides assistance to avoid panic situation for driver.
2017-01-10
Technical Paper
2017-26-0312
Sagar Polisetti, Ganeshan Reddy
Abstract Twist beam is a type of suspension system that is based on an H or C shaped member typically used as a rear suspension system in small and medium sized cars. The front of the H member is connected to the body through rubber bushings and the rear portion carries the stub axle assembly. Suspension systems are usually subjected to multi-axial loads in service viz. vertical, longitudinal and lateral in the descending order of magnitude. Lab tests primarily include the roll durability of the twist beam wherein both the trailing arms are in out of phase and a lateral load test. Other tests involve testing the twist beam at the vehicle level either in multi-channel road simulators or driving the vehicle on the test tracks. This is highly time consuming and requires a full vehicle and longer product development time. Limited information is available in the fatigue life comparison of multi-axial loading vs pure roll or lateral load tests.
2017-01-10
Technical Paper
2017-26-0313
Manoj Kumar Rajendran, Srinivasa Chandra V, Manikandan Rajaraman, Dinesh Kumar Rajappan, Agathaman Selvaraj
Abstract In today competitive world, gaining customer delight is the most vital part of an automotive business. Customers’ expectations are high which need to be satisfied limitless, to stay in the business. The major expectation of a commercial vehicle customer is a vehicle without failures which involves lower spares cost and downtime. The significance of a suspension system in the new age automobiles is getting advanced. There have been many improvements in the suspension system especially in leaf springs to provide a better ride comfort, and one such modern era implementation is the Parabolic Spring which comprises of fewer leaves with varying thickness from the center to the ends without inter-leaf friction. Study reveals that parabolic spring exhibits better ride comfort, but less life compared to a conventional leaf spring which leads to the increase in downtime of the vehicle.
2017-01-10
Technical Paper
2017-26-0310
Vyankatesh Madane, Sameer Shivalkar, Chandrakant Patil, Sanjeev Annigeri
Abstract In rubber industry, different techniques are used to enhance durability. This paper gives complete design, development and testing methodology of rubber bush in which pre-compression of rubber is used to enhance rubber bush life. In bogie suspension, axle to torque rod join is critical as it has to transfer lateral and longitudinal load with flexibility. This makes challenging to design joint which need to carry more than 6 ton load and having flexibility of more than 10 degree articulation. In this torque rod to axle joint called as End bush, compressed rubber is used to carry high load with flexibility. Other possible material for bush can be brass bush which able to carry high load however not able to give high flexibility Design and finite element calculations are done to design pre-compression and rubber volume to get desired strength and stiffness to carry required load with flexibility.
2017-01-10
Technical Paper
2017-26-0315
Jyoti Kale, Satish Kumar, Pravin Lavangare, Anand Subramaniam
Abstract The Steering system is one of the most safety critical systems in an automobile. With time the durability, reliability and the fine-tuning of the parameters involved in this subsystem have increased along with the competitiveness of the market. In a competitive market, accelerated testing is the key to shorter development cycles. It is observed that the majority of component manufacturers have a preference on vehicle level testing to achieve their development goals. The vehicle level trials are time consuming and lack the control and repeat-ability of a laboratory environment. This paper describes the development of a steering test rig designed to simulate the disturbances experienced on road within a controlled laboratory environment. The five axis steering rig would allow simulation of individual road wheel displacement along with steering wheel angle input and lateral steering rack displacements. The rig also is designed to be adaptable to a range of vehicle categories.
2017-01-10
Technical Paper
2017-26-0293
Sachin lambate, Kedar Shrikant Joshi, Gautam Diwan, Pratap Daphal
Abstract Steering column and steering wheel are critical safety components in vehicle interior environment. Steering system needs to be designed to absorb occupant impact energy in the event of crash thereby reducing the risk of injury to the occupant. This is more critical for non-airbag vehicle versions. To evaluate the steering system performance, Body block impact test is defined in IS11939 standard [1]. Nowadays for product development, CAE is being extensively used to reduce development cycle time and minimize number of prototypes required for physical validation. In order to design the steering system to meet the Body Block performance requirements, a detailed FE model of Body Block impactor is required. The static stiffness and moment of inertia of body block are defined in SAE J244a [2]. The reference data available in SAE J244a is not sufficient to develop a Body Block model that would represent the physical impactor.
2017-01-10
Technical Paper
2017-26-0299
Mahesh Kishore Patekar, Jeevan Patil, Sivakumar Palanivelu, Bhupendra Bhat
Abstract Brake system is the most important system in the vehicle considering the overall vehicle safety and speed control. Brake applications are repetitive during a city traffic and hilly terrain on downhill gradient. Frequent braking gives rise to an overheating of the brake drum and its components. Braking operations at high temperature gives rise to problems like reduced deceleration due to loss of brake pad friction characteristics, pad softening and sticking to drum, pad distortion and wear etc. All these factors collectively result in deterioration of the braking performance and reduction of brake pad durability with time. Till date most of the thermal analysis performed for brake drum heating are through physical testing using brake system prototypes and by means of CFD tools. These methods are time consuming and expensive. There is a need for an alternative method to reduce physical trials and prototype building and reduce dependency on CFD analysis.
2017-01-10
Technical Paper
2017-26-0292
Irshad Mahammad, Vinay Nagaraj, Saurabh Prabhakar
Abstract To replicate on-road brake test cycle of cooling or heating through Computational Fluid Dynamics (CFD) simulations, the vehicle model with brake assembly must be solved in transient mode. However, such simulations require significant computational time owning to the physics involved in computing the variation of temperature with time. A methodology developed using commercial CFD tools to predict the Heat Transfer Coefficient (h), Cooling Coefficient (b) and rotor temperatures is described in this paper. All the three modes of heat transfer: conduction, convection and radiation are considered in the current method. Heat transfer coefficients from the CFD simulations are exported to Computer Aided Engineering (CAE) tools to validate the Brake Rotor Thermal Coning caused by high thermal gradients in brake rotor.
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