Search Results

In automotive body manufacturing the dies for blanking/trimming/piercing are under most severe loading condition involving high contact stress at high impact loading and large number of cycles. With continuous increase in sheet metal strength, the trim die service life becomes a great concern for industries. In this study, competing trim die manufacturing routes were compared, including die raw materials produced by hot-working (wrought) vs. casting, edge-welding (as repaired condition) vs. bulk base metals (representing new tools), and the heat treatment method by induction hardening vs. furnace through-heating. CaldieTM, a Uddeholm trademarked grade was used as trim die material. The mechanical tests are performed using a WSU developed trimming simulator, with fatigue loading applied at cubic die specimen’s cutting edges through a tungsten carbide rod to accelerate the trim edge damage. The tests are periodically interrupted at specified cycles for measurement of die edge damage.

Automotive multiplexing allows sharing information among various intelligent modules inside an automotive electronic system. In order to achieve an optimum functionality, the information should be exchanged among various electronic modules in real time. New features are introduced in automobiles such as Intelligent Vehicle Highway System (IVHS), intelligent transportation support system, engine immobilizers, night vision assistance system, and automated collision avoidance and notification system. The inclusion of such features increases the data traffic over the multiplexing bus. Also, these features require very high speed and expensive bus. Data reduction techniques are used to send the data over a transmission media at high speed. Using the data reduction techniques, we will be able to include new features in automobiles without the need of a high speed bus. Since the automotive environment is different, a special data reduction algorithm is mandated.

Contemporary manufacturing systems are still evolving. The system elements, layouts, and integration methods are changing continuously, and ‘collaborative robots’ (CoBots) are now being considered as practical industrial solutions. CoBots, unlike traditional CoBots, are safe and flexible enough to work with humans. Although CoBots have the potential to become standard in production systems, there is no strong foundation for systems design and development. The focus of this research is to provide a foundation and four tier framework to facilitate the design, development and integration of CoBots. The framework consists of the system level, work-cell level, machine level, and worker level. Sixty-five percent of traditional robots are installed in the automobile industry and it takes 200 hours to program (and reprogram) them.

A new friction testing system has been designed and built to simulate the actual engine conditions in friction and wear test of piston-ring and cylinder liner assembly. Experimental data has been developed as Friction Coefficient / Crank Angle Degree diagrams including the effects of running speed (500 and 700 rpm) and ring normal load. Surface roughness profilocorder traces were obtained for tested samples. Mixed lubrication regime observed in the most part of the test range. New cylinder bore materials and lubricants can be screened easily and more reliable simulated engine friction data can be collected using this technique.

It is recognized that there is a dearth of studies that provide a comprehensive understanding of vehicle-occupant system dynamics for various road conditions, sitting occupancies and vehicle velocities. In the current work, an in-house-developed 50 degree-of-freedom (DOF) multi-occupant vehicle model is employed to obtain the vehicle and occupant biodynamic responses for various cases of vehicle velocities and road roughness. The model is solved using MATLAB scripts and library functions. Random road profiles of Classes A, B, C and D are generated based on PSDs (Power Spectral Densities) of spatial and angular frequencies given in the manual ISO 8608. A study is then performed on vehicle and occupant dynamic responses for various combinations of sitting occupancies, velocities and road profiles. The results obtained underscore the need for considering sitting occupancies in addition to velocity and road profile for assessment of ride comfort for a vehicle.

A unified approach has been developed and applied to solder joint life prediction in this paper, which indicates a breakthrough for solder joint reliability simulation. It includes the material characterization of solder alloys, the testing of solder joint specimens, a unified viscoplastic constitutive framework with damage evolution, numerical algorithm development and implementation, and experimental validation. The emphasis of this report focuses on the algorithm development and experimental verification of proposed viscoplasticity with damage evolution.

Vehicle weight-driven design comes amid rising higher fuel efficiency standards and must meet the criteria—pass proving ground (PG) test events that are equivalent to customer usage. Computer-aided engineering (CAE) fatigue analysis for PG is a successful push behind to digitally simulate vehicle durability performance with high fidelity. The need for vehicle weight reduction often arises in the vehicle development final phases when CAE methods, time, and tangible cost-effective opportunities are limited or nonexistent. In this research, a new CAE methodology is developed to identify opportunities for lightweight hole placement in the chassis structure and deliver a cost-effective lightweight solution with no additional impact on fatigue life. The successful application of this new methodology exhibits the effectiveness of the truck frame, which is the key chassis structure to support the body, suspension, and powertrain.

There is little agreement in the field of driving safety as to how to define cognitive distraction, much less how to measure it. Without a definition and metric, it is impossible to make scientific and engineering progress on determining the extent to which cognitive distraction causes crashes, and ways to mitigate it if it does. We show here that different studies are inconsistent in their definitions of cognitive distraction. For example, some definitions do not include cellular conversation, while others do. Some definitions confound cognitive distraction with visual distraction, or cognitive distraction with cognitive workload. Other studies define cognitive distraction in terms of a state of the driver, and others in terms of tasks that may distract the driver. It is little wonder that some studies find that cognitive distraction is a negligible factor in causing crashes, while others assert that cognitive distraction causes more crashes than drunk driving.

During the extensive testing under NATO and Commercial Standards, crack is observed in camshaft housing to initiate from the eccentric shaft bore and go toward the hold down bolt hole. Hence lab test proposal is originated to induce similar failure in a controlled method and then to compare new design alternatives. CAE analysis follows the same set up as the lab test to duplicate failure mode in stress analysis and fatigue analysis with duty cycle loads, and then figures out two strategies on how to improve the design, including geometry change and material change. In geometry wise, four new design iterations are evaluated for comparison. In material wise, one new material for camshaft housing and five manufacturing effect parameters for pin and rocker arm are compared, including ground, machined, machined and decarburization, casting, as well as casting and nitride. With those comparisons, all manufacturing parameters are compared based on effectiveness to affect the fatigue life.

Evaluations of the dynamic and acoustic responses of panels, partitions, and walls are of concern across many industries, from building home appliances, planning meeting rooms, to designing airplanes and passenger cars. Over the past few decades, search efforts for developing new methodologies and technologies to enable NVH engineers to acquire and correlate dynamically the relationship between input excitations and vibro-acoustic responses of arbitrary-shaped panels has grown exponentially. The application of a particular methodology or technology to the evaluation of a specific structure depends intimately on the goals and objectives of the NVH engineers and industries.

The present work is concerned with the objective of developing a process for practical multi-disciplinary design optimization (MDO). The main goal adopted here is to minimize the weight of a vehicle body structure meeting NVH (Noise, Vibration and Harshness), durability, and crash safety targets. Initially, for simplicity a square tube is taken for the study. The design variables considered in the study are width, thickness and yield strength of the tube. Using the Response Surface Method (RSM) and the Design Of Experiments (DOE) technique, second order polynomial response surfaces are generated for prediction of the structural performance parameters such as lowest modal frequency, fatigue life, and peak deceleration value. The optimum solution is then obtained by using traditional gradient-based search algorithm functionality “fmincon” in commercial Matlab package.

Nowadays, as an irreplaceable means alongside CAD and testing, CAE is more and more widely applied with advanced material modeling and simulation methods continuously being explored, so as to get more accurate result as testing. In vehicle product development process, door slam durability evaluation is an important measurement for body closure structure. So far numerous effort has been taken to develop more mature methods to well define door slam simulation in stress and fatigue life analysis. Overall all methods ever being applied can be summarized as two categories, linear stress based method and nonlinear stress based method. The methodologies, such as inertia relief method, direct transient response solution, or local strain approach, can be included in linear stress based method with linear material properties as symbol in CAE model. In local strain approach, contact surface could be defined in the necessary area with consideration for more realistic load transfer.

Wall-wetting due to liquid fuel film motion and fuel droplet impingement on combustion chamber walls is a major source of unburned hydrocarbons (UBHC), and is a concern for oil dilution in PFI engines. An experimental study was carried out to investigate the effects of injection timing, a charge motion control device, and the matching of injector with port geometry, on the “footprints” of liquid fuel inside the combustion chamber during the PFI engine starting process. Using a gasoline-soluble dye and filter paper deployed on the cylinder liner and piston top land surfaces to capture the liquid fuel footprints, the effects of the mixture formation processes on the wetted footprints can be qualitatively and quantitatively examined by comparing the wetted footprint locations and their color intensities. Real-time filming of the development of wetted footprints using a high-speed camera can also show the time history of the fuel wetting process inside an optically accessible engine.

Low back pain has a higher prevalence among drivers who have long term history of vehicle operations. Vehicle vibration has been considered to contribute to the onset of low back pain. However, the fundamental mechanism that relates vibration to low back pain is still not clear. Little is known about the relationship between vibration exposure, the biomechanical response, and the physiological responses of the seated human. The aim of this study was to determine the vibration frequency that causes the increase of muscle activity that can lead to muscle fatigue and low back pain. This study investigated the effects of various vibration frequencies on the lumbar and thoracic paraspinal muscle responses among 11 seated volunteers exposed to sinusoidal whole body vibration varying from 4Hz to 30Hz at 0.4 g of acceleration. The accelerations of the seat and the pelvis were recorded during various frequency of vibrations. Muscle activity was measured using electromyography (EMG).

The Wayne State University (WSU) EcoCAR2 student team is participating in a design competition for the conversion of a 2013 Chevrolet Malibu into a plug-in hybrid. The team created a repeatable on-road test drive route using local public roads near the university that would be of similar velocity ranges contained in the EcoCAR2 4-Cycle Drive Schedule - a weighted combination of four different EPA-based drive cycles (US06 split into city and highway portions, all of the HWFET, first 505 seconds portion of UDDS). The primary purpose of the team's local on-road route was to be suitable for testing the team's added hybrid components and control strategy for minimizing petroleum consumption and tail pipe emissions. Comparison analysis of velocities was performed between seven local routes and the EcoCAR2 4-Cycle Drive Schedule. Three of the seven local routes had acceptable equivalence for velocity (R₂ ≻ 0.80) and the team selected one of them to be the on-road test drive route.

The short NiTi fiber-reinforced NiTi/Al6061-SiC composite was recently developed through the U.S. Army SBIR Phase-II program [1]. The objectives of this project are to use short NiTi fiber reinforcement to induce compressive stress through shape memory effect, to use silicon carbide (SiC) particulate reinforcement to enhance the mechanical properties of the aluminum matrix, to gain fundamental knowledge of short NiTi fiber-reinforced aluminum matrix composite, and eventually to improve fatigue resistance, impact damage tolerance and fracture toughness of the composite. The fatigue life, damage and fracture behavior of TiNi/Al6061-SiC, TiNi/Al6061, Al6061-SiC composites as well as monolithic Al6061 alloy were investigated under fully reversed cyclic loading. It was found that fatigue life of NiTi/Al6061-SiC composite, in term of the cycles, increased by two orders of magnitude, compared to monolithic Al6061 alloy

Over the past decade there has been significant development in Automated Driving (AD) with continuous evolution towards higher levels of automation. Higher levels of autonomy increase the vehicle Dynamic Driving Task (DDT) responsibility under certain predefined Operational Design Domains (in SAE level 3, 4) to unlimited ODD (in SAE level 5). The AD system should not only be sophisticated enough to be operable at any given condition but also be reliable and safe. Hence, there is a need for Automated Vehicles (AV) to undergo extensive open road testing to traverse a wide variety of roadway features and challenging real-world scenarios. There is a serious need for accurate Ground Truth (GT) to locate the various roadway features which helps in evaluating the perception performance of the AV at any given condition. The results from open road testing provide a feedback loop to achieve a mature AD system.

A review of the literature dealing with the injury tolerance of the lower extremities in quantitative terms is provided. The data stem from sources ranging from Weber (1859) to as recent as Culver (1984) and in all cases involve tests of embalmed or unembalmed cadaveric specimens. The strength of the femur (thigh bone) and tibia (shin bone) have been depicted primarily in terms of the peak axial compressive force or bending moment associated with fracture-producing tests. Peak forces involved in fracturing the patella (knee cap) are reported for static and dynamic distributed loads involving both padded and rigid contact surfaces. One study is described where patella data are available for punch-through type fractures resulting from loading by small diameter impactors. Limited data are provided for hip joint dislocation and/or pelvic fracture as a result of loading through the femur. Finally, limited data are also included for injury at the knee and ankle joints.

Artificial Intelligence (A.I.) and Big Data are increasing become more applicable in the development of technology from machine design and mobility to bio-printing and drug discovery. The ability to quantify large amounts of data these systems generate will be paramount to establishing a robust infrastructure for interdisciplinary autonomous applications. This paper purposes an integrated approach to the environment, pre/post data processing, integration, and system security for robust systems in intelligent transportation systems. The systems integration is based on a FPGA embedded system design and computing (EDGE) platform utilizing image processing CNN algorithms from High Energy Physics (HEP) experiments in data centers with associative memory to ROS- FPGA technology in vehicles for hyper-scale infrastructure scalability. The ability to process data in the future is equivalent to collision particle detection that the Large Hadron Collider (LHC) produces at CERN.

There is a general interest in the reduction of cooling loads in military vehicles. To that end thermal barrier coatings (TBCs) are being studied for their potential as insulators, particularly for military engines. The effectiveness of TBCs is largely dependent on their thermal properties, however insulating effects can also be modified by applying different coating thickness. Convection from in-cylinder surfaces can also be affected by manipulation of surface structure. Although most prior studies have examined TBCs as a means of increasing efficiency, military vehicle design is primarily concerned with the reduction of cylinder heat transfer to allow downsizing of cooling systems. A 1-D transient conjugate heat transfer model was developed to provide insight into the effects of different TBC designs and material selection on cooling loads. Results identify low thermal conductivity and low thermal capacitance as key parameters in achieving optimal heat loss reduction.