High prestress truss cable support principle and its application in large cross section coal roadway

With the enlarge of cross section of roadway, the radius of plastic area and broken area increase, and the tensile stress and shear stress distributing in roof coal-rock layers relevantly increase, which induce support effect not obvious for ordinary bolt（cable）. While bounding point and support structure of the truss cable is in vertex angle of roadway, and supplies coal-rock layers in bounding area with the horizontal and vertical pressure, so it settles the support problems in large cross section coal roadway. From the point of view of mechanics, gave emphasis on the invalid mechanics of ordinary bolt （cable） in large cross section coal roadway and supported mechanics of prestress truss cable. The author successfully used this technique in Wuyang Mine, and had the huge economic efficiency and the social benefit.

以减轻重量为目标的索网桁架式可展开太空天线结构的优化设计

针对索网桁架式可展开天线的结构特点和性能要求,对其结构初始设计进行了优化研究。选取天线的桁架单元壁厚和索单元半径为设计变量,并对不同类型的设计变量进行了合理的归并,继而以结构重量为优化目标,以表面精度和基频为约束条件,建立了优化设计数学模型。考虑到索网结构有限元分析给计算带来的非线性和复杂性,使用序列二次规划法对模型求解,并给出了相关动力特性的敏度分析。通过算例分析可知,采用上述优化计算方法可以在保证天线工作性能的前提下有效地降低结构的重量,同时由优化迭代过程中约束函数值的变化情况可知,在一定范围内减小桁架单元壁厚和增大索单元半径,可以有效地提高天线表面精度和改善结构动力性能。