Research on cross-sectional shape to improve mass efficiency of high-strength thin plate hollow frame bending strength

Abstract

From the viewpoint of suppressing global warming, it is required to reduce CO2 emissions during driving by improving the fuel efficiency of automobiles. For that purpose, it is necessary to reduce the weight of the vehicle body frame to reduce running resistance. The most important function required of the frame member is the strength function to secure a space for the occupants to survive in the event of a collision. In general, the weight reduction and strength functions of the frame are in conflict, and structural design technology that suppresses cross-sectional collapse is important. We studied the plate shape that controls the in-plane bending buckling of the vertical plate of the cross section with the aim of suppressing the cross-sectional collapse of the automobile body frame formed of thin and high-strength steel sheets and utilizing the material strength of the steel sheet. From the theory of post-buckling strength of thin plates, we focused on the support conditions of the vertical plate and clarified the relationship with the shape of the peripheral structure. In addition, we derived a new shape proposal that suppresses buckling based on the shape of the vertical plate itself, and confirmed that it is possible to develop a buckling resistance that approaches the theoretical value that directly constrains the periphery.

Keywords

• thin-plate
• high stength steel
• hollow flame
• post-buckling strength
• in-plate bending