帽形截面耐撞薄壁结构的棱边强化与优化设计

为了满足车身轻量化要求，乘用车耐撞车身的关键承载结构越来越多采用超高强度薄钢板制作。但是为减小板厚而提高材料强度可能引发平板屈曲，导致薄壁箱型结构受压侧的极限承载力的降低。为此，根据平板和圆柱壳棱边的屈曲理论，讨论帽形截面的薄壁箱型结构受压侧的有棱边强化平板的后屈曲极限承载力。通过CAE数值模拟，求得单向均匀压缩带棱边强化平板的横截面应力分布和极限承载力。从而明确用棱边强化钢板部件替代热成形钢板部件在乘用车耐撞结构中应用的可行性。最后，梳理了棱边强化设计应用的前景和后续待研究的课题。

Ridgeline Strengthening and Optimization of Thin-walled Hat-section for Crashworthiness Structure

In order to meet lightweight requirement, ultra-strength steel plate has been utilized on major structures in automobiles for crashworthiness. However, both increasing yield strength and decreasing thickness can induce buckling which weakens the load-bearing capacity of the compression side of thin-walled box structure. Based on the buckling theories of plate and quarter cylindrical shell ridgeline, the load-bearing capacities of the ridgeline and the post-buckling plate on the compression side of hat-section box structure are discussed. The stress distribution and the load-bearing capacities in the cross-section of uniaxial compression plate with strengthened ridgeline are obtained in CAE simulations. Thus, the usefulness of replacing hot stamping steel components by utilizing those treated with ridgeline strengthening is confirmed for crash worthiness on major structures of passenger vehicle. In the end, further studies about the lightweight and crashworthiness for vehicle structures are discussed.