轮辐式马鞍形单层索网结构索长和外联节点坐标组合随机误差影响分析

Combined random error effect analysis of cable length and outer-linked-node coordinates of spokewise saddle-shaped monolayer cable net structure

通过随机误差影响分析索长误差和外联节点坐标误差对索力的影响特性,确定合理的误差控制指标.对比了定值分布、均匀分布和正态分布3种索长误差分布模型,分析了环索和径向索的长度误差对索力的影响,探讨了不同索长误差控制标准.计算结果表明,环索力受径向索长误差影响较小,径向索和环向索的索力受环索索长误差影响基本一致.索长误差限值越小,外联节点的安装误差限值越大.各榀外联节点的安装误差限值不同,高处限值比低处小.为满足索力误差不超出±10%的要求,案例工程控制指标为:拉索制作长度误差应不超出索长的±0.01%,低处和高处外联节点沿径向索方向的坐标误差应分别不超出±83和±67 mm.

According to the random error effect analysis,the influence of the cable length error and the outer joint coordinate error on the cable force was analyzed,and the reasonable error control index was determined.Three kinds of the cable length error distribution models with the fixed value distribution,the uniform distribution and the normal distribution were compared.The influence of the length errors of the ring cable and the radial cable on the cable force was discussed,and the error control standards of different cable lengths were discussed.The results show that the ring cable force is less influenced by the length error of the radial cable.The influence of the ring cable length error on the radial cable and that on the ring cable are basically the same.Smaller the limit of the cable length error,larger the limit of the installation error of the outer joint.Different outer joint coordinates have different installation error limits,and the error limit of the higher site is smaller than that of the lower site.To meet the requirements that the cable tension error is not more than±10%,the control indexes of this case are the production length error of the cable no more than±0.01%of the cable length,the lower joint coordinate error of the outer node in radial direction no more than±83 mm,and the higher joint coordinate error of the outer node in radial direction no more than±67 mm.