Optimum Design Of Composite Pipe By Imitating Structure Of Haversian System In Animal Bone

Composite pipe is made from two or more kinds of materials, has various characters, and is compounded by physical and chemical methods. The pipe has many advantageous features. It is light and has high intensity, good stiffness and low cost. It is clean and healthy. It possesses less resistance in transporting liquid. Thus, there are wide applications for the pipe in urban water supply and waste water discharge. However, cracks and ruptures occur in the former structures during the construction of prop pipe. The thesis focus on the optimum design of the composite pipe by imitating structure of haversian system in animal bone, in order to improve the stiffness and crack resistance, to meet the requirement of prop pipe construction, and to reduce costs.Firstly, micro model of constitutive equations of osteon. was established By Donnell-Mushtali hypothesis, osteon mode was simplified, control equations for the buckling of laminated composite cylindrical shell was obtain.. Adopting Double Fourier Progression Method, the general solution for the buckling of laminated composite cylindrical shells, as well as the analytic solution for simply-supported in two side laminated composite cylindrical shells, is worked out. Then, the buckling load is calculated to a example. After that, the relationship between bulking load and laminated angle, as well as the relationship between bulking load and slenderness ratio, is analyzed. Then, the finite element analysis for composite pipe of linear and nonlinear bulking is carried out. And the stress value and displacement value of the are obtained. The distortion, stress value and the displacement value in the first three of linear bulking are also worked out. The bulking load of nonlinear buckling is solved by finite element analysis as well. Finite element analysis software is used to optimum design for structure of composite pipe. After optimum design, the maximum displacement of composite pipe is greatly reduced and the materials used are significantly cut down. Lastly, the analytical result is compared with collagen orientation patterns in human secondary osteons of obtained by the Maria-Grazia.