Study Of Two-dimensional Pipe-network Carrier Used Self-healing Of Resin Matrix Composite

Micro-cracks, delamination and other internal defects always produce inevitably during the use of composites. If not repaired, these defects will shorten the life of the material and result in serious security risks. Duing to these inner defects inspected difficultly, self-healing technology of the composite appears, which can automatically repair damages of the material(eg micro-crack), without human intervention. In this paper, the two-dimensional network carrier in resin matrix composite have a study.Firstly, establishing void volume fraction threshold of the network through experiments and finite element analysis method. Preparation of epoxy matrix specimens, the tensile and bending test, the experimental results obtain epoxy relevant mechanical parameters that elastic modulus, Poisson’s ratio and ultimate strength, and be verified through finite element analysis. The values of parameters are 3.93 GPa, 0.34 and 20.6MPa respectively. By the finite element modeling and simulation, void volume fraction threshold of the two-dimension pipe-network carrier is 5.24%.Secondly, the two-dimensional orthogonal self-healing network carrier is studied. At a given total inlet flow rate, according to the selected diameter range, void volume fraction and flow efficiency of the network to be the optimize targets, using the improved multi-objective genetic algorithm NSGA-II, combined with Hardy Cross iterative method, the parameters are optimized for the two-dimensional network carrier model of SISO and DIDO. The result: after 12000 iterations, the network models of SISO and DIDO converge and the void volume fraction are within the threshold range, which shows the feasibility of this optimization algorithm. Through normalization process to elect the optimal topology scheme from the Pareto solutions, they are respectively 50 and 44 non-inferior solution, then calculating each pipe flow velocity, flow rate, etc.Finally, the fluid flow characteristics are studied for a two-dimensional network carrier flow channel by analytic and numerical simulation methods. The optimal topology programs of SISO and DIDO network model are the research object, using software Gambit mesh, boundary conditions for the velocity inlet and free flow, which flow pattern is laminar. Using Fluent software to simulate the network internal flow field, after the iterative procedure pressure, velocity and vector contours are obtained, observing the status and trends of liquid flow in pipe network, and calculating each pipe liquid flow velocity. Contrasted to the simulation and optimization speed, the speed values are close. At the same time compared with cracks and crack-free model of SISO state-dimensional network, the result obtain that some of the liquid flow out from the crack and the velocity of pipe decreases.