Research On Some Key Problems Of 80MN Multifunctional Testing Machine

The intended-to-build 80 MN multifunctional testing machine is currently the largest and most comprehensive giant machine in the world, which can be used to simulate the performance of mega civil structures and components under the complex load conditions such as the combination of compression, bending, torsion and dynamic cyclic loading. In this paper, the numerical simulation and analysis of several key issues in the design of 80MN multi-functional testing machine system were carried out. The main research contents and conclusions are listed as follows:(1) The function requirements of the testing machine were analyzed and structure parameters of the reaction frame were put forward. The characters of the working conditions in the test of huge reinforced concrete columns, concrete shear walls and large rubber bearing were analyzed.(2) The working principle of the loading platform with hydrostatic bearing pads was described and the force analysis was carried out. The anti-overturn capacity of the platform was checked and the impacting of the sudden breaking of the specimens on the platform was analyzed.(3) The finite element analysis model of the reaction frame was established and the static simulations were carried out under several load conditions such as in the testing of massive concrete columns and shear walls. The stress, strain and deformation of the reaction frame under the extreme loads were obtained.(4) For the test of the large rubber-steel bearing, the nonlinear finite element machine-bearing model was established with the Mooney-Rivlin material model, The stress and deformation in the reaction frame during the static compress-shear testing and the cyclic compressing-shear testing of the bearings were gotten respectively.(5) The dynamic analysis of the load frame was carried out. The inherent modal parameters and the dynamic response of the structure under dynamic loads were obtained.