交错桁架结构动力特性的简化分析方法

Simplified Analysis Methods of Dynamic Characteristic of Staggered Truss Structure

根据交错桁架结构质量和刚度分布比较均匀的特点,构造了一个与其质量和刚度分布相近的假想结构,并给出了假想结构各阶频率和振型的简化计算公式;基于矩阵摄动理论,给出了交错桁架结构和假想结构之间质量、刚度、自振频率和振型之间的关系表达式及其系数的计算公式,采用该理论对交错桁架结构自振频率、振型及地震效应进行了算例分析。结果表明:该方法避免了迭代计算,计算工作量小,且可以计算结构的各阶自振频率和振型;用该方法计算的自振频率及振型与精确解吻合较好;高层交错桁架结构采用底部剪力法和采用振型分解反应谱法计算的结构作用效应相差明显。

An imaginary structure whose mass and stiffness were close to staggered truss structure＇s was created according to that staggered truss structure has more uniformly mass and stiffness distribution, and the simplified design formulas to calculate the frequency and vibration mode of hypothetical structure were proposed. Based on the matrix perturbation theory, the formulas about the relationship expression and the coefficient in the expression of the mass, stiffness, natural vibration frequency, vibration mode between the staggered truss structure and the hypothetical structure were proposed. At last, the theory proposed in this paper was applied to analyze the natural vibration frequency, vibration mode, and earthquake effect of examples. The results show that the method in this paper can prevent the interactive calculation and decrease the calculating work load, and the method can also calculate the respective natural vibration frequency and vibration mode of structure, which has a better coincidence with the accurate method, while the disparity between the structural effect applied with the equivalent base shear method of high-rise staggered truss structure and the structural effect applied with the vibration mode superposition method was significant.