Applied Mechanics and Materials Vols. 204-208

Abstract: As one of the common hazards to buildings, cracks will directly affect the bearing capacity and life of the structure. The pressure grouting introduced to the restoration project of Sanqing Hall of Huixian Taoist Temple has been proved efficient with character of simple and speedy execution and effective crack strengthening.

Abstract: In order to get the interface fracture curve of different materials under the four-point loading test pieces, firstly the displacement of fracture interface was obtained based on the finite element method. Then the first and second stress intensity factors of two different materials interface cracks in a beam specimen were calculated by the extrapolation method. Comprehensively considered the type of fracture specimen and the relative proportions between first and second section stress intensity, the variables K' , the first and second stress intensity factor were calculated according to the observed values of fracture load when the fissure appeared. By regression analysis of a six-groups of rock-concrete specimens with prefabricated fissure, the interface fracture criterion of different materials was got which was the interface fracture curve of rock-concrete samples. At last the calculated results of this method were compared and verified with the other related research results.

Abstract: Using finite software ANSYS LS/DYNA for simulating the impact response and failure modes of H section steel frame columns subject to blast loads，and loading different load conditions, changing column boundary conditions and web plate thickness. Conclusion: the failure model of steel columns changes with the change of load form,steel columns will be easy to occur shear failure in the end by the dynamic load, and the flange will be easy to occur bucking failure in local by impulse load; In the case of same size and web thickness, increase the web thickness can reduce the deformation of column effectively, improve the capability of H section steel column resist the blast load.

Abstract: The nonlinear stability of three main piers of Xiniu bridge was analysed with RM Bridge V8i in this paper. The change of high pier’s nonlinear stability with the strength decline of high pier’s local concrete and variation of high pier’s height were also respectively researched.The results show that nonlinear stability coefficients will be lower if one segment of high pier’s concrete strength declines. It also indicate that the nonlinear stability coefficients drop is related to the decrease of the concrete strength, the distance between the segment at the bottom of pier, and the height of pier.

Abstract: In this paper, seven reinforced concrete beams (two contrast beams and five externally reinforced beams) were tested. The crack regularity under different tension stresses was analyzed through experimental data. Taking the stress mode under pressure for the triangle area, in the tension zone in the shape of a trapezoid , the crack resistance equation of externally prestressing reinforced rectangle beam is derived from balance method of the internal forces and moment, and the results coincide with the experiment results well.

Abstract: Rebar corrosion test of Carbon Fiber Reinforced Polymer (CFRP) concrete was did. Carbon fiber in concrete improved the compression strength of the concrete, but width and number of concrete cracks was not reduced, carbon fiber has not obvious act for improving concrete corrosion crack behavior. CFRP concrete Corrosion potential was a little high than common concrete, carbon fiber has not obvious act for improving concrete behavior in protecting steel beyond corrosion. The porosity of the carbon fiber reinforced polymer concrete was twice of the common concrete, carbon fiber added to concrete lead to increase porosity and maybe decrease concrete behavior in protecting the embedded steel in corrosion.

Abstract: Fracture test was performed on conventional joint of steel box column-H steel beam. The test results indicate that the conventional joints brittle fracture at butt weld of beam flanges. The performance of joints of steel box column-H steel beam strengthened with haunches is numerically simulated based on an ellipsoidal fracture model considering of welding residual stress and welding defects. The simulated results show that, for the joints of box column-H beam strengthened with haunches, the plastic rotation of could reach 0.03rad and the bearing capacity increased by 20% compared with that of the conventional joint.

Abstract: Through the experiment of eight lightweight aggregate reinforced concrete beams under static loading and fatigue loading with constant amplitudes, the deformation rule under fatigue loading was analysed, the rigidity calculation means and formulations of lightweight aggregate reinforced concrete beam under fatigue loading were also discussed.

Abstract: The ANN-based optimization for considering fatigue reliability requirements in structural optimization was proposed. The ANN-based response surface method was employed for performing fatigue reliability analysis. The fatigue reliability requirements were considered as constraints while the weight as the objective function, the ANN model was adopted to establish the relationship between the fatigue reliability and geometry dimension of the structure, the optimal results of the structure with a minimum weight was reached.

Abstract: This paper takes the under-frame of 300t storage silo produced by a certain company as the main research subject,static behavior of the under-frame is analyzed by three-dimension finite element method to generalize the rule of static deformation and stress distribution.Eigenvalues can be obtained by stability analysis and global stability and the whole structure is checked.All of the above provide a reliable reference for the design of storage silo.