[关键词]
[摘要]
为探讨大学生结构设计竞赛常用竹条或竹皮制作的不同类型空心杆的基本力学性能,为参赛者模型制作选择合适的截面尺寸,用0.2 mm,0.35mm,0.5mm竹皮和2*2和3*3mm竹条制作了123个长度为100 mm的不同边长的正方形空心杆试件,应用电子压力试验机测试了其极限承载力,并分析了其破坏形式、荷质比及试验与理论计算值的对比情况。试验结果表明:单层竹皮构件以棱角开裂为主,双层竹皮构件以受弯破坏为主,竹皮+竹条组合构件可避免上述两种破坏形式;单层竹皮构件以0.5 mm,边长为10 mm的构件具有较高极限承载力,但因手工制作原因导致极限承载力降低可达50%;0.5 mm双层竹皮构件的荷质比较大,可达400 N/g;单层竹皮+竹条组合构件的极限承载力在1000 N左右,荷质比在300~450 N/g之间,与双层竹皮相差不大,因手工制作导致的承载力降低较小,适合受力较大的杆件。
[Key word]
[Abstract]
In order to study the basic mechanical properties of different types of hollow bars made of bamboo strips or bamboo skin commonly used in the structural design contest for college students, and to select the appropriate section size for the model making of competitors, 123 pieces of samples made of bamboo skin with size of 0.2mm, 0.35mm, 0.5mm and bamboo strip with size of 2*2mm , 3*3 mm with 100 mm in length were made. The ultimate bearing capacity of hollow bar with different side length was tested by electronic pressure testing machine. And its failure form, load mass ratio and ratio of experimental and theoretical values were analyzed. The test results show that the single-layer bamboo skin component is mainly cracked by edges and corners. And the double-layer bamboo skin component is mainly damaged by bending; The composite component of bamboo skin and bamboo strip can avoid the above two kinds of damage forms; The single-layer bamboo skin component with 0.5mm in depth and 10 mm in width has a higher ultimate bearing capacity. However, the ultimate bearing capacity can be reduced by 50% due to manual manufacturing; The load mass ratio of the 0.5 mm double-layer bamboo skin component is the largest, up to 400 N/g; The ultimate bearing capacity of the composite component of bamboo skin and bamboo strip is about 1000 N. And the load mass ratio is between 300~450 N/g, which is not much different from that of the double-layer bamboo skin. The reduction of bearing capacity due to manual manufacturing is small. It is suitable for structures with large stress.
[中图分类号]
G642.423
[基金项目]
山西省高等学校科技创新项目(2019L0295);山西省教学改革创新项目“基于大学生结构设计大赛的学科竞赛管理体系研究”(2020JG012)