摘要
为研究人字形组合臂架结构的线性失稳载荷简易计算问题,进行了理论改进和仿真验证。首先从实体式人字形结构出发,采用柔度法推导出单柱轴向载荷算式,运用有限元和非线性拟合技术得到了法向铰约束下的等效约束系数,并结合算例检验了单柱近似失稳载荷算式的准确性;然后考虑剪力的不利影响,给出了人字形组合臂架线性失稳载荷算式;最后使用算式计算两种典型构件截面形式的28个人字形组合臂架结构,同时使用SAP2000软件对其进行线性屈曲仿真。结果表明:对于十字形腹杆体系的人字形组合结构,臂架长宽比在1.790-5.865大范围内修正算式的计算精度有显著提高;当长宽比大于3时,误差基本呈减小趋势,并保持在-3.2%以内。
In order to study the simple computational method of an linear stability--losing load of an inverted--V combinatorial jib, this paper completed theoretical improvement, simulation and verifi- cation. Firstly on the inverted--V structure of solid column,an axial load formula was obtained based on flexibility method. Then, the finite element method and non--linear fitting technique were applied to get the equivalent constraint factor of the inverted--V structure under the constraints of normal hinge, and the accuracy of the single--column approximate stability--losing load formula was tested with two practical examples. After that, with the effects of shear force considered, the linear stability-- losing load formula of the inverted--V combinatorial jib was proposed. After using the proved formu- las and software SAP2000 in linear buckling analysis of 28 combinatorial jibs consisting of two kinds of typical--section rods, the results demonstrate that.as for the inverted--V combinatorial jibs consis- ting of cross--shaped web members,when the aspect ratio of the inverted--V combinatorial jib is in the broad range of 1. 790-5. 865, the calculation accuracy of the formulas increases significantly,and the errors are decreased and less than --3.2 % when the aspect ratio is above 3.
出处
《中国机械工程》
EI
CAS
CSCD
北大核心
2013年第24期3323-3328,共6页
China Mechanical Engineering
基金
国家自然科学基金资助项目(51375345)
关键词
人字形组合臂架
空间压杆
线性稳定性分析
起重机
inverted--V combinatorial jib
space compressive structure
linear stability analysis
crane