考虑剪切及轴向变形时Γ形框架的弯曲计算

Bending Calculation ofΓ-Shaped Frame Considering Shear and Axial Deformation

当静不定Γ形框架受到水平集中力作用时,在考虑剪切和轴向变形的基础上,以水平方向是固定铰支撑、竖直方向是固定支撑的Γ形框架为例,讨论了静不定Γ形框架的弯曲变形。通过计算,得到了意想不到的结果:水平集中力作用在刚结点上,若不考虑剪切和轴向变形的影响,固定铰支撑水平方向支反力不为0,竖直方向支反力为0。研究结果表明:当杆件跨高比超过5时,材料力学教材、结构力学教材研究框架内力时,不考虑剪切及轴向变形的影响是可以接受的;对Γ形框架杆件进行强度校核时,不应忽略剪切及轴向变形的影响。

Taking a statically indeterminateΓ-shaped frame with fixed hinge supports in horizontal direction and fixed supports in vertical direction as an example,and considering shear and axial deformation,the bending deformation of the frame subjected to the horizontal concentrated force is discussed.After calculation,it is found unexpectedly that when the horizontal concentrated force acts on the rigid node,without considering the influence of shear and axial deformation,the horizontal support reaction of fixed hinge support is not zero,and the vertical support reaction is zero.The results show that it is acceptable for materials mechanics textbooks and structural mechanics textbooks to study the internal forces of the frame without considering the influence of shear and axial deformation when the span-height ratio is over 5.The influence of shear and axial deformation should not be ignored in the process of strength check ofΓ-shaped frame.