边界条件对复合材料储能飞轮应力及位移分布的影响

不同的边界条件对复合材料飞轮的应力、位移分布有着不可忽视的影响,和飞轮的储能密度也有相当的关系。针对复合材料和对称结构的特点,建立基于非均质各向异性弹性理论的计算模型,得到飞轮在工作转速情况下应力和位移计算的解析公式,给出了任一点的径向、环向应力及径向位移。并按照所建立的计算模型对飞轮的几何尺寸、转速对其应力、位移场的影响进行仿真计算,并对不同的边界条件对飞轮径向、环向应力和径向位移的影响进行比较。

两层预应力转子结构复合材料储能飞轮的应力及位移计算

采用预应力结构可使复合材料飞轮的应力、位移分布得到一定改善,从而提高飞轮储能密度。考虑复合材料和预应力结构的特点,建立基于各向异性对称结构理论的计算模型,得到两层预应力转子结构复合材料储能飞轮在工作转速情况下应力和位移的解析公式,对内、外两层飞轮任一点的径向、环向应力及径向位移进行较为全面的仿真分析,并利用所建立的计算模型对飞轮在某一转速时不同的位置对径向应力、环向应力和径向位移的影响进行探讨。结果表明,内层转子径向应力在外侧最大,环向应力在内侧最大;外层转子径向应力和环向应力均在内侧最大。当角速度ω从0增加到5000rad·s-1时,内、外转子的径向应力、环向应力和径向位移都随之增大。当ω=600rad·s-1,整个飞轮径向应力、环向应力和位移的最大值出现在两层转子的接触面r=0.27m处。该分析结果可为飞轮的设计制造提供重要的参考。

深井软岩巷道破坏原因及矿压显现规律

根据现场调查和实测结果,分析了马路坪矿软岩巷道围岩变形和破坏的主要原因。通过数值模拟计算,分析了巷道围岩破碎区、塑性区范围和应力位移分布规律,为巷道合理支护形式的选择提供理论依据。

马路坪煤矿深部岩巷矿压特征及围岩变形特性分析

文章根据马路坪矿深部软岩巷道表面位移的实测结果,分析了巷道围岩变形主要特征。通过数值模拟计算,探讨了巷道围岩破碎区、塑性区范围和应力位移分布规律,为巷道合理支护形式的选择提供了理论依据。

坚硬厚层顶板工作面切顶卸压沿空留巷技术研究

为使工作面上覆厚且坚硬的顶板能有序跨落,文章基于屯兰矿12408工作面相关工程条件,通过理论分析、数值模拟等方法,阐述了切顶卸压的基本原理,建立了相关力学模型,计算了切顶预裂的切顶角度与切顶高度,并通过数值模拟验证了切顶参数的合理性,研究结果表明:1.切顶卸压工艺能有效缓解12408工作面坚硬顶板垮落对留巷与充填体的影响;2.12408留巷合理的预裂角度为75°,切顶高度为10 m;3.切顶卸压后顶板在预裂缝处有明显的卸压现象,且顶底板采空区侧的垂直应力明显小于留巷侧的垂直应力,巷道垂直变形量为45~63 mm,整体变形不大,切顶参数选取合理。此研究成果为减缓坚硬顶板跨落对沿空留巷的冲击、减小留巷与充填体的变形量提供了参考。

Response models of weakly consolidated soft rock roadway under different interior pressures considering dilatancy effect

Surrounding rocks of weakly consolidated soft rock roadway show obvious strain softening and dilatancy effects after excavation. A damage coefficient concerning modulus attenuation was defined. Response models of stress and displacement of surrounding rock of soft rock roadway and analytical expressions to calculate plastic zones under different interior pressures and non-uniform original rock stresses were derived based on damage theories and a triple linear elastic-plastic strain softening model. Influence laws of dilatancy gradient on damage development, distributions of stresses and displacement in plastic region were analyzed. Interior pressure conditions to develop plastic region under different origin rock stresses were established and their influences on plastic region distribution were also discussed. The results show that the order of maximum principle stress is exchanged between ~0 and trr with the increase of interior pressure P0, which causes distributions of plastic zone and stress shift. Dilatancy effect which has great influences on the damage propagation and displacements in plastic region has little effect on the size of plastic region and stress responses. The conclusions provide a theoretical basis for a reasonable evaluation of stability and effective supporting of weakly consolidated soft rock roadway.

初应力对单向复合材料圆柱板周向波的影响

基于"增量变形力学"理论,研究了径向和轴向均匀初应力作用下单向复合材料圆柱板中周向波的传播特性,应用Legendre多项式法求解了耦合波动方程.讨论了单向复合材料纤维方向分别为周向和轴向时,初应力对圆柱板中的周向类Lamb波和SH波的影响.数值分析结果表明初应力对周向类Lamb波和周向SH波的影响是非常不同的;轴向初应力对频散曲线、位移和应力分布的影响与径向初应力的影响也不相同.