Stability Analysis Of Semi-Rigidity Single Layer Spherical Reticulated Shells And Its Joint System

Concerning the design of spherical shells, stability of single-layer spherical shells is the key problem, and the ascertainment of the accurate calculation-mode is very important to the analysis of the shell's stability. Usually, shells with weld-joint system are considered as rigid-joint system and shells with bolt-joint system are generally considered as pin-joint shells,but in fact,bolt-joint has capacity of bearing partial bend,it is semi-rigid system between rigid-joint and pin-joint。Further more,because of such shell's convenienct construction, beautiful apearence and merit of engineering application, the pertinency study of the shells with semi-rigid system has important practice purport.To get the curve of bending moment-rotation of bolt-ball exactly ,experimental analysis and numerical simulation based on accurate and large-scale complete-process analysis are considered in this text,and the curve of bending moment-rotation of bolt-ball are educed by studying the bend rigid character of bolt-ball. The experimental results are mostly consistent with the theoretical ones, which indicate that the numerical simulation is accurate and effective to simulate the bolt-ball's mechanical property. It can serve as stability base for design and application of the bolt-ball and other semi-rigid joints.The shells with bolt-joint system have been detailed analyzed in this dissertation based on bend stiffness (the results of the experiments) of common bolt joint system. The elasto-plastic complete process of k8 and k6 spherical shells are studied, the ultimate strength and buckling modes of shells are obtained, the effects of stability are observed systematically by varying different spans of shells, ratio of high and span, bend stiffness, rotation stiffness, the size of joint system, the load of dissymmetrical distributing, the types of bars, the condition of support and initial geometrical imperfection. The stability of shells with semi-rigidity of joint system is mastered by a comprehensive numerical analysis. The fitting equations for the stability checking computations of K8 and K6 spherical shells with bolt-joint systerm are axquired based on the equation form in the presence regulation using a great deal of data obtained from the upwards parameter analysis.