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In-cylinder ion sensing is a subject of interest due to its application in spark-ignited (SI) engines for feedback control and diagnostics including: combustion knock detection, rate and phasing of combustion, and mis-fire On Board Diagnostics (OBD). Further advancement and application is likely to continue as the result of the availability of ignition coils with integrated ion sensing circuitry making ion sensing more versatile and cost effective. In SI engines, combustion knock is controlled through closed loop feedback from sensor metrics to maintain knock near the borderline, below engine damage and NVH thresholds. Combustion knock is one of the critical applications for ion sensing in SI engines and improvement in knock detection offers the potential for increased thermal efficiency. This work analyzes and characterizes the ionization signal in reference to the cylinder pressure signal under knocking and non-knocking conditions.

It is important to understand the accuracy level of the formability analysis for any new process so that correct predictions can be made in product and die design. This report focuses on the formability analysis methodology developed for the preform anneal process. In this process, the aluminum panel is partially formed, annealed to eliminate the cold work from the first step, and then formed to the final shape using the same die. This process has the ability to form more complex parts than conventional aluminum stamping, and has been demonstrated on a complex one-piece door inner and a complex one-piece liftgate inner with AA5182-O3. Both panels only required slight design modifications to the original steel product geometry. This report focuses on the formability analysis correlation with physical panels for the liftgate inner, considering both full panel anneal in a convection oven and local annealing of critical areas.

An analysis of the first 35 back-over crashes reported by NHTSA's Special Crash Investigations unit was undertaken with two objectives: (1) to test a hypothesized classification of backing crashes into types, and (2) to characterize scenario-specific conditions that may drive countermeasure development requirements and/or objective test development requirements. Backing crash cases were sorted by type, and then analyzed in terms of key features. Subsequent modeling of these SCI cases was done using an adaptation of the Driving Reliability and Error Analysis Methodology (DREAM) and Cognitive Reliability and Error Analysis Methodology (CREAM) (similar to previous applications, for instance, by Ljung and Sandin to lane departure crashes [10]), which is felt to provide a useful tool for crash avoidance technology development.

Sensory jury testing was utilized to characterize vibration levels perceived by the operator, with respect to levels measured using instrumentation, in order to develop a tool for the evaluation of vibration at the operator interfaces. Details of the jury testing and jury data processing method are highlighted as well as the refinement of vibration characterization for a specific application. The vibration at user interface locations of both snowmobiles and ATVs was measured along with subjective feedback from a panel of jurists. Statistical analysis was performed on the jury data to provide both a qualitative and quantitative number to represent the opinion of the jury. Correlations were developed between the measured levels of vibration and the opinions of the jury. Finally, a set of correlation functions suitable for design predictions was developed.

Researchers desire to evaluate system reliability uniquely and efficiently. Despite its strong technical demand, little progress has been made on system reliability analysis in the last two decades. Up to now, bound methods for system reliability prediction have been dominant. For system reliability bounds, the second order bound method gives fairly accurate prediction for system reliability assuming that the probabilities of second-order joint events are accurately obtained. Two primary challenges in system reliability analysis are evaluation of the probabilities of second-order joint events and no unique system reliability for design optimization. Firstly, the greatest technical demand is found in an accurate and efficient method to numerically evaluate the probability of a second-order joint event.

This paper presents an innovative approach for quality engineering using the Eigenvector Dimension Reduction (EDR) Method. Currently industry relies heavily upon the use of the Taguchi method and Signal to Noise (S/N) ratios as quality indices. However, some disadvantages of the Taguchi method exist such as, its reliance upon samples occurring at specified levels, results to be valid at only the current design point, and its expensiveness to maintain a certain level of confidence. Recently, it has been shown that the EDR method can accurately provide an analysis of variance, similar to that of the Taguchi method, but is not hindered by the aforementioned drawbacks of the Taguchi method. This is evident because the EDR method is based upon fundamental statistics, where the statistical information for each design parameter is used to estimate the uncertainty propagation through engineering systems.

New tire model is under development in European Commission research project called VERT (Vehicle Road Tire Interaction, BRPR-CT97-0461). The objective of the project is to create a physical model for tire/surface contact simulation. One of the subtasks has been to develop a method for snow surface characterization. The aim is simulate winter tire on snow surface with FEM software. This kind of simulation has been earlier done with snow model parameters from laboratory experiments. A snow shear box device has been developed in Helsinki University of Technology to measure mechanical properties of snow in field conditions. Both shear and compression properties can be measured with the device. With the device, a large number of snow measurements have been done at the same time with VERT winter tire testing in Nokian Tyres'' test track in Ivalo Finland. Measurement data have been postprocessed afterwards and parameters for material models have been evaluated.

This paper deals with the dynamic characterization of an automotive shock absorber, a continuation of an earlier work [1]. The objective of this on-going research is to develop a testing and analysis methodology for obtaining dynamic properties of automotive shock absorbers for use in CAE-NVH low-to-mid frequency chassis models. First, the effects of temperature and nominal length on the stiffness and damping of the shock absorber are studied and their importance in the development of a standard test method discussed. The effects of different types of input excitation on the dynamic properties of the shock absorber are then examined. Stepped sine sweep excitation is currently used in industry to obtain shock absorber parameters along with their frequency and amplitude dependence. Sine-on-sine testing, which involves excitation using two different sine waves has been done in this study to understand the effects of the presence of multiple sine waves on the estimated dynamic properties.

Small electric DC (Direct Current) motors used to actuate various mechanisms in vehicles have failed prematurely when exposed to some formulations of lubricants, which leached into the motor and caused shorting. The subject study explored this failure mechanism in detail as evidenced in vehicle power door lock actuators. Experiments were conducted through the application of various types of lubricants to motors in varying ways to re-create the failure mode experienced by the authors, and to determine an optimized selection of lubricant for maximized cycle life, robust to inherent component manufacturing process variation in both the amount and location of lubrication placement. The detailed data, photographs and conclusions which resulted were summarized. The electric motor failure mode experienced in the example situation was first explained and illustrated with detailed photography.

The increasing usage of brake-by-wire systems in the automotive industry has provided manufacturers with the opportunity to improve both vehicle and manufacturing efficiency. The replacement of traditional mechanical and hydraulic control systems with electronic control devices presents different potential vehicle-level safety hazards than those presented by conventional braking systems. The proper design, development, and integration of a brake-by-wire control system requires that hazards are reasonably prevented or mitigated in order to maximize the safety of the vehicle operator, occupant(s), and passers-by.

Decoratively plated plastic parts continue to be in high demand. One of the essential and challenging features of these finished goods is the adhesion between the metal plating and the plastic. As is the case with any bond between metals and plastics, combating the force from dissimilar thermal growth is an ongoing concern. When a plated plastic part is frozen and the plastic contracts, the failure mode for the plating manifests as a blister or “worm track”. On the other hand, when high heat causes plating failures from growth of the plastic, the problem is one of cracking in the plating. In this study, two methods are discussed that provide insight into the strength of the bond between the metal plating and the ABS and ABS+PC plastics. Peel testing is one means to evaluate the strength of the plating to plastic bond. Peel testing methodology and results are reported for both ABS and ABS+PC samples. A second means to evaluate the bond strength is through thermal cycle testing.

Driver out-of-position (OOP) tests were developed to evaluate the risk of inflation induced injury when the occupant is close to the airbag module during deployment. The Hybrid III 5th percentile female Anthropomorphic Test Device (ATD) measures both sternum displacement and chest acceleration through a potentiometer and accelerometers, which can be used to calculate sternum compression rate. This paper documents a study evaluating the chest accelerometers to assess punch-out loading of the chest during this test configuration. The study included ATD mechanical loading and instrumentation review. Finite element analysis was conducted using a Hybrid III - 5th percentile female ATD correlated to testing. The correlated restraint model was utilized with a Hybrid III - 50th percentile male ATD. A 50th percentile male Global Human Body Model (HBM) was then applied for enhanced anatomical review.

The engineering of electric propulsion systems requires time and cost efficient methodologies to determine system characteristics as well as potential component integration issues. A significant part of this analysis is the identification of the electromagnetic fields present in the propulsion system. Understanding of the electromagnetic fields during system operation is a significant design consideration due to the use of components that require large current(s) and high voltage(s) in the proximity of other control system items (such as sensors) that operate with low current(s) and voltage(s). Therefore, it is critical to quantify the electromagnetic fields produced by these components within the design and how they may interact with other system components. Often overlooked (and also extremely important) is an evaluation of how the overall system architecture can generate or react to electromagnetic fields (which may be a direct result of packaging approaches).

Coolant pipes are a prime connection units present in any engines that facilitates the flow of coolant and thereby keeping the engine under its optimum operating condition. Among the several influencing factors that deteriorate engines performance, the coolant leak is also one of the contributors. This could be caused primly due to leakage issues that arises from the pipe press fit zones. Henceforth it is very important to understand the root cause of this press-fit connection failure. The present study deals with press-fit between the pipe and housing in an engine which is subjected to extreme thermal loads (min of -40°C to a max temperature of +150°C) thereby causing the press-fit loosening effect.

Accurate material property data in both the elastic and plastic ranges of deformation is essential for accurate material representation in finite element simulations of vehicle systems. Variation of post formed material properties across a part are often of interest in different types of analyses, such as metal forming or fatigue life, for example. Depending on a part's shape it is not always possible to cut standard size tensile test specimens from all areas of interest across the part. Smaller size specimens with curved or tapered gage section may have to be used to promote strain localization and fracture at or near the gage center. This paper presents comparison of quasi-static tensile properties determined using two specimen gage section geometries, straight and tapered. Specifically, the following questions are addressed. How do the engineering strains computed from two-dimensional strain fields obtained by DIC compare to strains measured during standard tensile tests?

One of the most critical and important fracture mechanisms in a FMVSS207/210/225[1] test is the pull-thru of bolts from the body structure or spot weld separation. There are no analytically proven methods of making a judgment of pull-thru occurring except through evaluation of the plastic strain or through the thickness strain value around projection welds on Weld nut/stud bolt or spot welds. Therefore it is essential to have accurate criteria to evaluate the pull-thru. During elastic deformation, the sheet steel deforms while the quasi-static force is being applied and then returns to its original shape when the force is released. But when the force causes a stress that exceeds the yield strength, the sheet steel will permanently elongate with each additional unit of force applied, and it will not return to its original shape and size.

For many years, the computer aided math model has been the foundation for lowering cost and reducing time to market for many manufacturing industries. The automotive industry applies a variety of tools and methods to evaluate the expected vehicle performance to a forever expanding set of requirements. These mathematical predictions of performance are then repeated for both a set of design cycles and a multitude of vehicles in the product portfolio. This paper presents a CAE perspective of the unique problems of the large scale virtual vehicle engineering factory and a set of solutions. Different strategies to create the various complex math models required are explored. These strategies include using COTS FEA pre-processers, producing FEA models internal to the CAD tools, as well as custom built tools, macros and process automation tools.

Dynamic modal frequency structural analysis incorporating ADAMS/Flex dynamic load prediction and structural modal stress can provide accurate dynamic stress history for fatigue analysis and synthesis. The amount of data input to finite element analysis is reduced significantly compared to traditional modal & direct transient finite element analysis techniques. Compared to traditional dynamic loads prediction, no additional simulation effort is required except for incorporating flexible body models of structural components into the ADAMS model. This structural analysis technique seamlessly comprehends the correct geometry and force boundary conditions together for long duration dynamic stress calculations. This technique also provided the solution for the deficiency of traditional quasi-static inertia relief method, which is particularly significant for structural system with either significant deformation or articulation.

This paper describes an analytical methodology for predicting the fatigue life of a door system for check load durability cycles. A check stop load durability cycle occurs when a customer opens the door beyond the door detent position with a force applied on the check link or hinge check stops. This method combines Finite Element Analysis (FEA) model and fatigue code to compute the durability requirements. The FEA model consists of Door-in-White (DIW) on body with integrated hinge check link or independent check link. Nonlinear material, geometric and parts contact were considered for the door with body-in-white (BIW). Several door hinge designs, with integrated and independent check links, were investigated. Using the Von Mises stress and plastic strain from the above analysis, the fatigue life was predicted and compared with the test data. Integrating FEA and fatigue allows predicting the threshold total strain value, which is developed, for check load durability requirements.

The size and complexity of embedded software in automotive systems has been increasing rapidly. This makes the analysis of such systems difficult. For instance, in many analyses it is required to trace the dependences between variables in the software. E.g., in checking compliance to On-Board Diagnostics (OBD) standards one needs to ensure that only OBD compliant data-items are used (directly or indirectly) in an algorithm that is to be OBD compliant. Similarly, for safety analysis such as Design Failure Mode Effects Analysis (DFMEA), all the inputs to a safety critical system, all inputs to them, etc., have to be found, so that failure modes associated with these can be analysed. Currently such tracing of dependences is performed manually at great cost and effort. We describe the application of a technique (and tool) that automates the tracing of software dependence.