Search Results

For a crash analysis using FEM with respect to a structure that is composed of thin plates, we developed a new structure study method (plastic strain equalization method). This method defines the optimality criteria as in the linear analysis of a fully stressed design and indirectly finds an optimal solution. We assume that a structure with both a lightweight and high collapse load should have sufficient strength corresponding to impact loads in each area. This means that at any area the load value and the strength are balanced at a certain value. For the criteria that the plastic strain value is equal over the whole area, a solution can be found by repeating computations. The design variable is the thickness of shell elements and the computation is iterated until plastic strain values are almost equal. In this paper, a structure with both a lightweight and a high collapse load could be optimized by equalizing the plastic strain value.

Improvement of indicated thermal efficiency of internal combustion engines is required, and increasing the compression ratio is an effective solution. In this study, using a CAE analysis coupling a 0-dimensional combustion analysis and a 1-dimensional heat conduction analysis, the influence of compression ratio on indicated thermal efficiency and combustion was investigated. As a result, it was found that there was an optimal compression ratio that gave the best indicated thermal efficiency, because the increase of cooling loss caused by high compression was bigger than the increase of theoretical indicated thermal efficiency in some cases. Next, the influence of cooling loss reduction on the optimal compression ratio was investigated. It was found that indicated thermal efficiency improved by reducing cooling loss, because the compression ratio which made the best indicated thermal efficiency was shifted to higher compression ratio.

First, this paper describes a measurement of the human back-backrest interface contours and a reduction procedure of the measured contours to reconstruct the statistical back contours of American 50 and 95-percentile male. Second, the paper illustrates the difference of the back contour between the statistical male drivers and SAE 3-D Manikin. Finally, the advantage of using the back contour model in experiment is given. The AM 50 back contour model was used as a loader to obtain the backrest pressure distribution and proved an excellent tool for backrest comfort evaluation.

A structure which effectively improves compatibility in a vehicle-to-vehicle frontal impact has been considered focusing on sub-frame structure that disperses applied force with multiple load paths. Evolved sub-frame structure has been studied by CAE with RADIOSS to search the possibility to reduce aggressivity and to improve self-protection at the same time. Vehicle models used for this compatibility study were a large saloon car with sub-frame and a small family car without sub-frame. The large saloon car had three different front structures: original, forward-extended sub-frame, and original with 25%-stiffness reduced structures. The types of collision contained four different crash modes in a combination of lateral overlap rate difference and side member height difference.