摘要
基于最优穹顶温室缩尺模型承力面面积比例分配计算得上3层横梁及竖梁相应荷载,在ANSYS中进行逐级静力仿真,与雪载模拟应变试验对比,结果表明,微应变与加载质量呈线性相关,试验相关系数为0.9932~0.9999,仿真相关系数为0.9948~1,仿真与试验微应变相对误差为1.840%~8.386%,仿真方法可靠。对1层横梁和竖梁在网格尺寸为10、12、16、18、20 mm时进行静力仿真,结果表明,模型半径在0.24 m时,适宜的网格尺寸为16~18 mm。在ANSYS中,采用同样方法计算仿真加载值,对半径6 m的穹顶温室12组方案进行初选、线性屈曲、力学校验(刚度、强度、稳定性)等逐步分析,得到共4层、第1层梁数为8、混合分叉结构为最优方案;对半径12、18 m的穹顶温室最优结构进行屈曲仿真,结果表明,在水平荷载作用下1阶初始模态缺陷明显,在竖直、水平荷载作用下,非线性屈曲荷载平均为线性屈曲荷载的0.37、0.57倍,说明有必要对大跨度穹顶温室进行非线性屈曲分析,以保证其结构足够稳定;力学校验皆合格,且半径为6、12、18 m温室的稳定性校验值在组合2作用下分别为组合1作用下的1.89、2.26、2.33倍,强度在2种组合作用下差别不大;与1152 m^2 Venlo型连栋玻璃温室相比,3种尺寸温室单位体积用钢量可节约40.11%~59.34%。
Upper three layers load values of the horizontal and vertical beams were based on the proportional distribution of bearing surface area from scaled model of optimal dome greenhouse,which were stage-by-step static simulated in ANSYS software and compared with snow-loaded simulated strain test.The results showed that micro-strain was linearly related to the loading mass,correlation coefficients in tests was in the range of 0.9932~0.9999 and in simulation was in the range of 0.9948~1,relative errors of micro-strain between simulation and test were in the range of 1.840%~8.386%,which indicated that the simulation method was reliable.Static simulations on one 1ayer with the mesh size of 10 mm,12 mm,16 mm,18 mm and 20 mm were carried out,the results showed when radius was 0.24 m,most appropriate mesh size was 16~18 mm.In ANSYS,12 schemes of 6 m greenhouse were analyzed step by step through primary selection,linear buckling and mechanical verification(stiffness,strength and stability)by using the same simulation loading calculation method,and optimal scheme was obtained,that was four layers,the first layer had eight beams and mixed bifurcation structure.Buckling simulations on optimal structure of dome greenhouse with radius of 12 m and 18 m was carried out,which obtained the first-order initial modal defects were obvious under horizontal loads,and under vertical and horizontal loads,non-linear buckling loads were 0.37 and 0.57 times of linear buckling loads on average,which was necessary to carry out nonlinear buckling analysis for long-span dome greenhouse in order to ensure sufficient structural stability.Mechanical verifications were all qualified,stability values of 6 m,12 m and 18 m greenhouses under combination 2 are 1.89,2.26 and 2.33 times of that under combination 1,respectively,and there was little difference in strength under two combinations.Compared with 1152 m^2 Venlo multi-span glass greenhouse,steel consumptions per unit volume of three size greenhouses can be saved by 40.11%~59.34%.
作者
于海业
关姝杰
刘爽
隋媛媛
YU Haiye;GUAN Shujie;LIU Shuang;SUI Yuanyuan(College of Biological and Agricultural Engineering,Jilin University,Changchun 130022,China)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2019年第11期331-340,共10页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家高技术研究发展计划(863计划)项目(2013AA103005-04)
关键词
穹顶温室
分叉结构
有限元分析
屈曲分析
力学校验
dome greenhouse
branching structure
finite element analysis
buckling analysis
mechanical verification
