钢结构反力架系统力学性能研究

Study on mechanical properties of steel structure reaction frame system

钢结构反力架系统是开展土木工程结构静力、拟静力试验的重要设备。在试验过程中,钢结构反力架系统的力学性能将直接影响试验结果的可靠性。因此,该文以拟静力试验加载全过程的钢结构反力架系统为研究对象,通过测点布置钢结构反力架的关键受力位置,使用软件Midas对刚度变化进行有限元分析,验证有限元模型的正确性。结果表明:在水平荷载加载前后,同位置测点应力最大相差28.08%,各测点应力变化较小;Midas计算的钢柱应力与对应试验测点应力最大相差21.64%,钢梁应力与对应试验测点应力最大相差23.97%;在竖向荷载情况下,钢梁Midas位移计算结果与参考手册的误差为18.92%,但通过理论与有限元误差分析发现,Midas计算模型更符合实际边界条件,位移计算结果也更准确;选取相应的设计规范对钢梁进行刚度校核,发现钢梁的刚度条件远小于各规范的限值,证明钢结构反力架系统满足设计和大型试验加载精度的要求。该文的研究结果可为工程结构实验室钢结构反力架系统的设计和优化提供参考。

Steel structure reaction frame is an important test instrument to carry out static and quasi-static tests of civil engineering structures.In the test process,the mechanical properties of steel structure reaction frame will directly affect the reliability of the test results.Therefore,in this paper,the steel structure reaction frame involved in the whole process of pseudo-static test loading is taken as the research object,the key stress position of the steel structure reaction frame is arranged by measuring points,Midas is used to carry out finite element analysis of its stiffness changes,and verify the correctness of the finite element model.The results show that the maximum difference of stress at the same position is 28.08%before and after horizontal loading,and the change of stress at each measuring point of steel structure reaction frame is small.The maximum stress difference calculated by Midas between steel column and the corresponding test point 21.64%,and the maximum stress difference between steel beam and the corresponding test point 23.97%.Under vertical load,the error between the Midas displacement calculation results and the reference manual's calculation results of beam end consolidation is 18.92%.Through theoretical and finite element error analysis,it is found that the Midas calculation model is more consistent with the actual boundary conditions,and the displacement calculation results are more accurate.Select the typical design specification to check the stiffness of steel beam,it is found that steel beam stiffness conditions are far less than the limit of the specification,steel structure reaction frame meets the design and large test loading accuracy requirements.The results of this paper can provide reference for the design and optimization of steel structure reaction frame system in engineering structure laboratory.