The Relation of Bending Buckling Strength in Vehicle and Three Point Bending Maximum Strength of Door Impact Beam

도어 임팩트 빔의 3점 굽힘 최대강도와 차량 장착 시 굽힘 좌굴강도와의 관계

Abstract

First, three point bending analysis for the inclined press door impact beam was carried out to investigate inclination angle effect on the maximum strength with varying support distance. Next, for the system model with spring elements representing body stiffness at door mounting area, the bending structural behavior of impact beam mounted on vehicle was estimated. The mounting distance and inclination angle were changed and the beam bending buckling strength was presumed at the head displacement below which spring stiffness change has little effect on the load. Finally strength ratio to predict the bending buckling strength of impact beam mounted on vehicle from three point bending maximum strength of fixed support distance was suggested.

Fig. 1 Door impact beam

Fig. 2 FMVSS 214 side impact pole test

Fig. 3 Press door impact beam section

Fig. 4 Three point bending analysis model of TB_600_0°with different overhang length

Fig. 5 Load-displacement curve from three point bending analysis of TB_600_0° with different overhang length

Fig. 6 Load-displacement curve from three point bending analysis of L_tb=600mm

Fig. 7 Deformed shape of TB_800_20°

Fig. 8 System analysis model of L_s=950mm, θ=20°

Fig. 9 Spring stiffness

Fig. 10 System analysis model of L_s=855mm

Fig. 11 Load-displacement curve from system analysis

Fig. 12 Deformed shape of SS_855_20° at head displacement100mm and 200mm

Fig. 13 Strain energy from system analysis

Fig. 14 Load-displacement curve from system analysis of Ls=950mm model with changed spring stiffness

Fig. 16 Strength ratio SR₄₀₀ and SR₅₀₀

Fig. 15 Load-displacement curve from system analysis of Ls=760mm model with changed spring stiffness

Table 1 Maximum strength from three point bending analysis

Table 2 Strain energy from system analysis(a) Strain energy

Table 3 Impact beam buckling strength

Table 4 Maximum strength from three point bending analysis of support distance 400mm and 500mm