Applied Mechanics and Materials Vols. 578-579

Abstract: Predicting the dynamic response of a floating and submerged structure subjected to underwater explosion is greatly complicated by the explosion of a high explosive, propagation of shock wave, bubble-pulse, complex fluid-structure interaction phenomena and the dynamic behavior of the floating structures. A numerical simulation has been carried out to examine the behavior of elliptical submersible pressure hull to non-contact underwater explosion (UNDEX) and take the effect of bubble-pulse. The finite element package ABAQUS was used to model the UNDEX and the fluid-structure interaction (FSI) phenomena. The pressure wave resulting from an UNDEX was assumed to be a spherical wave. Plastic strain and the time histories of the wet-surface displacement, velocity and von Mises stress are presented. The analytical results are valuable for designing underwater vehicles to resist UNDEX.

Abstract: The paper achieved the nonlinear analysis of bearing capacity of recycled concrete filled steel tubular short columns by using finite element analysis software ABAQUS. In order to meet the finite element analysis the writer put forward the modified formula of recycled concrete constitutive relationship of core, and elaborate d the contact at the interface of steel tube and the core concrete and related modeling points. Finally the load-deformation curves of the finite element analysis and test results coincide well. It indicates that the modified formula of recycled concrete constitutive relationship can better meet the requirements of analyzing bearing capacity of recycled concrete filled circular steel tubular columns under compressive Loading by using ABAQUS. Through the simulation experiment, it is useful for us to obtain the ultimate reliable bearing capacity of the similar structure member.

Abstract: The objective of this paper is to provide the references through finite element analysis for steel tube concrete beams bearing capacity settlement. The paper verified the correctness of the constitutive relation of concrete, the correctness and the model through the establishment of the concrete damaged plasticity model with recycled concrete details in the finite element analysis software ABAQUS. Then the stress characteristics of steel pipe concrete beam in bending condition under different substitution rate could be found through model calculation. The result is that the mid span bending - strain curve from simulation agreed to the experimental results, and the model is proved correct. Finally it came to the conclusions. Other things being equal, the recycled concrete filled square tube changed a lot in bending state when the substitution rate grows, but it didn’t occur to the circular one. In the meantime, the writer proposed the conjecture on the bearing capacity calculation of the two types of structure.

Abstract: Finite element analysis methods were conducted to investigate the seismic performance of panel zone at the connection of square steel column and two H-shaped beams with different heigth level by using ABAQUS. Compared with the previous test ,which verifies the correctness of finite element model. The paper sets up a total of 11 finite element analysis models, The changes of the web thickness, thickness of beam flange, diameter-thickness ratio in the finite element analysis models are studied, Which affect the beam end joint load - displacement curves and stress distribution.Studies have showed that: the beam flange thickness ratio and the beam offset ratio has insignificant influence on the load-displacement curves. The diameter to thickness ratio have sharp influence on the load-displacement curves.

Abstract: In this paper, in order to understand fully the development of failure mechanism, bearing capacity and seismic performance of the steel H-beams and composite concrete filled steel tubular (CFST) column joints strengthened by outside strengthening ring, in the space zone the effects of changing the axial compression ratio is investigated. A 3D joint finite element model is built up by finite element software ABAQUS, the elastic-plastic finite element analysis is carried through numerical modeling process. The analysis results showed that low axial compression ratio has a little influence on the bearing capacity; with the increase of axial pressure the bearing capacity will decrease in a high axial compression ratio, moreover the failure pattern of joint changes from beam end to column end. The ductility of the specimens is decreased by raising axial compression ratio.

Abstract: The article researches seismic performance of joints of cellular steel column and steel beam by finite element simulation. Finite element model is established by using the finite element software reasonably. Considering about the hole position and the distance of center of hole as invariant moments, under low cyclic loading we can attain hysteretic curves and skeleton curves etc. which are compared and analyzed in different opening rate by simulated software. The results show that for a certain axial compression ratio (n=0.45) of joints of cellular steel column and beam, the reasonable opening rate can improve the seismic behavior of the joints.

Abstract: This paper simulates the separate lock with shear keys or with flat joints under different design conditions using the ANSYS programme, analyze the mechanical effect of the shear keys. The variation law of the joint opening，the vertical displacement and foundation stress of lock chamber in different working condition are investigated. The research shows that the joint opening is biggest under high water-level condition, but simultaneously, the influences of shear keys on the lock chamber structures is small. The vertical displacement and foundation stress of separate lock chamber with trapezoidal shear keys or with flat joints show the similar variation law. Under overhaul condition and built up lock chamber condition, the joint opening of lock with shear keys is smaller than that of lock with flat joints. Under the same conditions, the biggest vertical displacement of the lock with shear keys is smaller than that of lock with flat joints, and the foundation stress distribution of the former is more uniform.

Abstract: Gravity platform was widely used in the development of marginal oil field, but the existence of scour pit caused by the flow and wave increasing the possibility to overturn. The paper introduced the no depth contact interface element to simulate the nonlinear effect between the bucket skirt and soil, and introduced the birth-death element to simulate the increasing scour pit. The results provide guidance to prevent overturning.

Abstract: In order to research the damage identification of reticulated shell, the damage identification of reticulated shell was taken on though two-step identification method on the basis of the optimal placement of sensors. The measuring points can be determined according to the optimal placement of sensors, which can be analyzed by the wavelet toolbox of MATLAB, in which make the change rate of modal strain energy the damage index. Then the measuring points of second step can be found. The damage placement can be identified from the second step by the change rate of modal strain energy. The result shows that: the two-step method is feasible.

Abstract: In this paper, the finite element analysis software ABAQUS is used to study the seismic performance of the joints of rectangular steel tubular columns filled with steel-reinforced concrete and H-shaped steel beam in different beam strengths, which are under the same axial compression ratio of 0.2. By the finite element simulation, we can get the load-displacement curves and skeleton curves from the end of H-shaped steel beam. According to the curves and dates, the seismic performance of the joints is analyzed. The shape of each restoring force curves presents for full square spindle, reflecting that the beam-column structure can effectively absorb the seismic energy; with the enhancement of H-shaped steel beam’s strength, the ultimate bearing capacity of the structure is gradually increasing, however, the stiffness and overall stability of the components become worse by degrees; the change of ductility property about the joints is not obvious, showing good seismic performance.