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In the last few years, there has been a greater emphasis on using advanced lightweight materials in automotive applications, primarily to realize better fuel economy and cost-effectiveness. In response to the demand for such materials, many new grades of steel are now available that offer a wide variety of mechanical properties and manufacturability indices. The new class of steel, known as Advanced High Strength Steels (AHSS) offer better strength-to-weight ratios than conventional cold rolled steels, and could be utilized to design cost effective structures. The paper will discuss the application of using the AHSS steel in an automotive rear seat frame structure. The items to be discussed include the manufacturability of AHSS, the load transfer method of such structures, joining methods used in such an application, and design challenges of modeling in FEA. Test results of seat structures with a comparative analysis with FEA will be reviewed.

In recent years, the design of automotive components and assemblies have resulted in an over-reliance on advanced CAE tools especially the Finite Element Analysis. An emphasis on cost reduction and commonization of components in automotive industry has made it necessary to use the CAE tools in innovative ways. Use of FEA as a effective product development tool can be greatly enhanced if it provides a high degree of correlation with physical tests, thereby greatly limiting the investment in expensive prototypes and testing. This paper will discuss a robustness based methodology to realize effective correlation of finite element models with actual physical tests on automotive seat structure assembly, at a component, sub-system, and systems level. Based on a parameter design approach, the various factors that affect the degree of correlation between CAE models and physical tests will be described.

Bolted joint separation occurs when components of a joint are no longer capable of maintaining a clamp load. The clamp load of a joint is the resultant of various factors such as the strength of joining components, geometry, and the surface condition of the joined parts. The fastener installation torque is a very critical parameter that contributes towards achieving the desired clamping force at the joint during the assembly process. Thread rolling screws are increasingly being used in many automotive structural applications. The thread rolling screws are easy to install, are self aligning, and offer a torque prevailing feature with improved vibration resistance when mated with a un-threaded nut. This combination results in a robust joint and low field costs. They also offer increased joint strength by work hardening the mating nut interface.