以6063铝合金薄壁梁结构为研究对象,采用准静态轴向加载的方式,借助WAW-E600型微控万能试验机,探明诱导孔结构对铝合金薄壁梁压缩变形行为与吸能性能的影响规律。研究表明:单排诱导孔能够使试样的变形模式由欧拉模式转变为混合模式,提高试样变形的稳定性,降低载荷峰值,吸能性能增加26.78%。多排诱导孔的位置与尺寸对薄壁梁的变形有较大影响,试样中部的诱导孔会降低结构稳定性,使试样失稳以欧拉模式变形为主,其载荷水平及吸能性能均较低;尺寸呈梯度变化的诱导孔能够使试样发生手风琴模式的变形,试样顺序压溃,载荷波动平稳,吸能性能较高;大尺寸诱导孔会使试样在局部发生剪切变形并逐层顺序压溃,其载荷平稳,是一种新的变形模式。通过实验数据对比,系统研究诱导孔尺寸对临界载荷的影响规律,并基于线形回归理论,建立铝合金薄壁梁结构临界载荷与截面惯性矩之间的定量关系。
The effect of cut-outs on deformation behaviors and energy absorption of 6063 aluminum with thin-walled structures will be investigated by quasi-static axial compression using WAW-E600 microcomputer controlled universal testing machine. The results show that the deformation mode of the aluminum extrusions is changed from Euler mode to Mixed mode after setting single line cut-outs on the specimen, and the energy absorption increases 26.78%. The deformation behavior is more stable and the peak force is lower than that of the complete sample during compression. The size and position of cutouts have very significant effects on axial collapse behaviors of aluminum thin-walled structure. The aluminum samples buckle under Euler mode with poor performance of deformation stability, loading force and energy absorption, because cut-outs locate in the middle of extrusions. Gradually changing size of cut-outs could leads that the compression behaviors become concertina mode. The aluminum extrusions collapse from top to bottom sequentially with steady load curve and excellent energy absorbing performance. Large cut-outs will introduce local buckling with shear deformation. The compression behavior is a new mode, which has stable load and successive collapse process. Based on the experimental data, the influence of cut-outs size on the critical force was studied. The relationship between critical force and inertia of the thin-walled structure was established by using linear regression.