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A key challenge in engineering design with elastomers for automotive applications, such as chassis suspension mounts and engine mounts, is to integrate fatigue life calculations into the design process. This will be required for life cycle engineering but is a difficult and complex task and this paper will outline some recent progress that has been made using a fracture mechanics approach together with a new finite element code, FLEXPAC, developed especially for this purpose. Finite element analysis enables the fracture mechanics approach to be generalised in principle to any geometry. In practice, however there have been serious difficulties in obtaining numerical solutions when rubber components containing internal cracks, whose surfaces are in contact, are modelled with large deformations and non linear elasticity properties. The overall problem has been approached in three parts. First, materials models are input for elasticity, stress softening and fatigue crack growth behaviour.

This paper gives an overview of an ongoing program of work aimed at developing a new life assessment methodology for bonded and weld bonded automotive structures. The approach involves the integration of three key requirements: environmental resistance, fatigue behavior in fracture mechanics terms and finite element analysis of joint design. A relatively simple laboratory fatigue test, suitable for typical automotive sheet materials, has been developed to assess the interaction of fatigue loading with environmental effects. From this, data are derived to: (a) compare the effects of various environmental conditions on adhesive systems, and (b) provide fundamental fracture mechanics data that can be used in the analysis of structures. The required fracture mechanics parameters for structures are obtained using finite element analysis (FEA). Validation of the method has been carried out by correlating the measured fatigue life of model automotive structures with the predicted behavior.

JPL is entering a new era of spacecraft (s/c) mission operations. The number of s/c tracked is steadily increasing. For many missions, the mission durations are getting longer and mission operations requirements are becoming more complex. For other missions, the emphasis will be on low cost and therefore a less elaborate mission operations undertaking. S/c engineering analysis is conducted to verify s/c engineering performance, characterize the s/c, determine s/c capability, track consumables, and support mission engineering analysis. Engineering analysis at JPL can be characterized by too much done manually, a lack of sufficient analysis tools, the uneven distribution of these tools among subsystems, the difficulty in generating predicts, and the lack of tight integration and therefore cumbersome interaction among subsystems. This paper discusses the concept of an integrated environment for engineering analysis which will enable increased productivity.

A Fortran computer code has been developed to simulate the performance of a turbocompound two-stroke diesel engine. This powerplant offers the potential for fuel efficiency combined with high power-to-weight ratio, and is being considered for airborne applications such as helicopters and drone aircraft. The simulation code allows the user to specify engine parameters for the diesel core, the turbocharger (in the form of a performance curve), the bottoming turbine, and the intcrcooler. The program runs in two modes. The user runs the design mode first, in which specification parameters are set and the code sizes the turbomachincry and intercooler. The off-design mode can then be run to see how the resulting engine will perform at off-design values of ambient conditions, fueling rate, and engine speed. The code has been developed to run on an IBM PC.