大学生结构设计竞赛受压空心长杆屈曲试验研究

Experimental study on buckling of long hollow rods for university students structure design contest

为探讨大学生结构设计竞赛常用竹皮制作的不同箱型空心长杆的轴压屈曲稳定性能,由不同队员采用竹皮制作了不同长度和截面形式的空心受压箱型长杆,测试了杆件的质量和极限承载力。试验结果表明:随杆件长度增加,受压长杆承载力和荷质比降低,双层竹皮长杆的荷质比可达140 N/g;现有竹材受压长柱计算公式能较为准确地计算其极限承载力;为提高竞赛成绩,应选择单层或双层竹皮制作的受压空心短柱作为结构设计模型杆件,但不同队员手工制作水平导致承载力差异较大,应着重处理角点等容易损坏的位置。

In order to study the bucking of different types of hollow rods made of bamboo skins commonly used in the structural design competition of college students,74 hollow rods with different lengths(200,250,300,350,400,450mm),different cross-section forms(single-layer and double-layer bamboo skins)with side lengths of 10 mm were made by different members using 0.35 mm and 0.50 mm bamboo skins.Then,the mass,bearing capacity were tested.The test results show that:with the increase of length,the bearing capacity and the load mass ratio decrease.And the load mass ratio of long member made by the 0.5 mm double-layer bamboo skin can reach 140 N/g;the existing calculation formula of the compressed long bamboo column can be used to calculate its ultimate bearing capacity;In order to improve the competitiveness,the hollow short rod with single-layer 0.5 mm or double-layer 0.35 mm(length less than 250 mm)should be selected as a design member.But the bearing capacity varies greatly due to different hand-made level of team members,so it is necessary to focus on the corner and other easily damaged positions.In order to study the bucking of different types of long hollow rods made of bamboo skins commonly used in the structural design competition of college students,the long hollow rods with different lengths and cross-section forms were made by bamboo skins.Then,the mass,bearing capacity were tested.The test results show that:with the increase of length,the bearing capacity and the load mass ratio decrease.And the load mass ratio of long member made by the double-layer bamboo skin can reach 140 N/g.The existing calculation formula of the compressed long bamboo column can be used to calculate its ultimate bearing capacity.To improve the competitiveness,the hollow short rod made with single-layer or double-layer should be selected as a design member.But the bearing capacity varies greatly due to different hand-made level of team members,so it is necessary to focus on the corner or other easily damaged positions.