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A Ti-6Al-4V alloy was rolled at different temperatures and subsequently annealed to obtain fatigue samples with different texture characteristics. The samples were then subjected to tension-tension high-cycle fatigue (HCF) tests and the fracture morphology was observed to correlate the texture characteristics with the HCF properties. The results show that the texture intensity significantly affects the HCF strength for the equiaxed microstructure of Ti-6Al-4V alloys with an equivalent grain size and the same texture type; also, the HCF strength decreases with increasing texture intensity. The fracture morphology observation and Schmid factor calculation show that planar facets, which are a characteristic feature of crack initiation sites, are formed due to the strength mismatch caused by the inhomogeneous slip distribution favored either for prismatic or basal slip. The effect of the texture intensity on the HCF properties can be explained by the influence of the number of pile-up locations of ‘soft’ grains neighboring ‘hard’ grains in the typical Stroh model that elucidates the planar facet formation mechanism.

In order to improve the efficiency of the calculation of the whole car side impact finite element model,simplified model often used in research of B-pillar in passenger car. It is critical to establish a high accuracy simplified model in a short time. The relationship between the energy absorption of body parts and the calculation accuracy of simplified model was analyzed,and the result can be used as a guide for the establishment of simplified model.

A new method is proposed to determine the maximum energy that absorbed by axial pressured thin wall tube. Three typical collision speeds are selected, which are low speed at 30km/h, medium speed at 60km/h and high speed at 90km/h. This paper also calculates the strain rates under different automotive collision conditions. Finite element software ABAQUS was used to investigate the effect of lightweight when circular thin wall tubes with different materials absorbing maximum and equal energy. The materials for thin wall tubes are high-strength steel, aluminum alloy and plain steel. The effect of lightweight of different material tubes in low strain rate, medium strain rate, and high strain rate can be obtained using the equal energy absorption strategy. The weight that reduced by high-strength steel tube and aluminum alloy tube is higher than that of plain steel tube, at all three strain rates.