Applied Mechanics and Materials Vols. 94-96

Abstract: Simulating real virtual ocean environment is necessary for the research of interaction simulation of underwater gravity aided inertial navigation system. One of the key techniques of realizing virtual ocean environment is modeling and simulating three-dimensional ocean waves. Numerical simulation of three-dimensional ocean waves in the case of different wind speeds is realized using MATLAB based on directional spectrum composed of Pierson-Moscowitz frequency spectrum and directional spreading function. Experiments show that the simulation speed is fast and the simulation results are vivid if suitable simulation frequency band, interval of wave frequency and interval of direction angle are selected. The simulation can provide some technological supports for interaction simulation of gravity aided navigation system for underwater vehicles.

Abstract: The finite element model of metal structure of 45 tons container stacker is established and Ansys software is employed to calculate the stress of key parts. The skill of model processing of the complete machine and the boundary condition of calculation model is described. The calculation results are used to guide the design of the container stacker.

Abstract: Using ANSYS / LS-DYNA to study the dynamic response of square steel tube beam filled with steel-reinforced high-strength concrete under impact loading at different speeds. The numerical simulation results show that: At different conditions of speed, the concrete failure modes are different. The combined action of Steel tube and steel flange makes the stress wave propagation extremely complex in the beam, when the speed increased to a certain value, it made damage to the internal steel flange and flange lateral concrete under impact load, while the concrete between the top of steel flange and steel tube was protected by the combined action.

Abstract: Different charge structure has an important influence on explosive energy efficiency and rock blasting effect. On the basis of Misses strength theory, using ANSYS/LS-DYNA to simulate the integrated rock blasting effects under different charge structure conditions, including continuous coupling charge, continuous decoupling charge and interval charge. And the effective stress-time curves of typical elements are compared to analysis. The results show that air as a decoupling medium plays a good buffer function, which is an ideal charge form. And interval charge has a better effect to buffer the pore wall peak pressure, thus reducing the destruction around the blast holes.

Abstract: In order to analyze the feasibility of barrier safety performance evaluation with computer simulation method, finite-element models of various vehicles and barriers were set up and simulations results are compared to multiple full-scale impact test data. The results indicate that all safety performance index such as vehicle trajectory, structural adequacy, occupant risk and dynamic deformation can be extracted from computer simulation and FEA results are coincident with those of tests with error less than 10%. Computer simulation method is proved to be highly feasible for safety performance evaluation of barriers. The concept that simulation models must be verified through tests is stressed and the suggestion that laws and regulations on professional audit and management of CAE engineers should be completed is brought out.

Abstract: Stiffness is one of the most important performance indicators of cars’ parts. Currently, most of the major automobile panels are made of big sheet metal, whose stiffness are relatively small, which lead to a lot of difficulties in measurement during practice. The high stiffness of fixed stiffness testing instrument with gantry structure makes the automobile panel measured precisely. The finite element model was established by ANSYS in order to study the effect of load at typical work locations on strength and stiffness, and the strength of testing instrument under maximum load was also illustrated. The results showed that the displacement of the load point and the work load performed the linear growth. When the testing instrument was imposed the maximum working load, the displacement of load point was less than the measuring precision. The strength and stiffness of the testing instrument met the requirements of operation.

Abstract: It’s extremely strict on crack of nuclear power plant containment for the durability and barrier to nuclear leakage. High concrete strength and large heat of hydration make it difficult to control construction cracks. At the foreign and domestic nuclear power plants delamination or subregion had been adopted normally for mass concrete construction, but still more cracks appeared, and had paid great costs to deal with them. Based on theoretical analysis, in the article the study on merge concreting and crack control technical of base slab of the current popular CPR1000 nuclear power plant containment is carried out. Through the analysis of thermal stress laws on the placement of the different thickness, different sliding ability, different curing methods and construction capabilities and influences of other installation and construction process under the merge concreting, the paper puts forward and validates the feasibility of the merge concreting, and propose many crack-prevention measures from the design, construction, monitoring of temperature stress and shrinkage and others. Finally, the merge concreting has been successfully applied, breaking the routine and having been achieved remarkable economic and social benefits.

Abstract: Combined with one specific engineering example, in which the novelty and complexity of the bridge has to be taken into account, a complex spatial simulation model including beam, plate, and solid elements is established by the application of MIDAS/Civil2006, then its internal force is calculated and analyzed. But through this method, the model is complex and the calculation efficiency is not high. So how to use the grillage theory to construct model for the bridge to improve the design efficiency is necessary. Specifically, the model is established only by beam elements, in which compression-flexure member, shear-bending member is simplified as grillage or column case. The result of the comparative analysis on the two models shows that both the support reaction and the internal force or stress are in agreement under the dead weight and moving load, as well as the fundamental frequency and vibration. So the result of the simplified model according grillage for unitary analysis has sufficient precision. And the simplified method can provide some reference for spatial analysis of other similar bridges.

Abstract: In order to solve the insufficient bearing capacity of the large-diameter circular steel tube K-Joints, the chord in the joint zone is filled with the concrete. The reinforcement of bearing capacity that the concrete makes to K-Joints is researched with the finite element numerical simulation method, in consideration of the material nonlinearity and the geometric nonlinearity. The numerical computation of bearing behavior is employed to eighteen groups of the large-diameter circular steel tube K-Joints and reinforced ones with the concrete (RK-Joints). The failure styles and the influencing factors of bearing capacity are analyzed with RK-Joints. The result shows that the bearing capacity of K-Joints is enhanced significantly by the concrete filled in the chord in the joint zone. The load-deformation curves reveal the changing regularity that the bearing capacity of joint follows the relevant parameters. It can provide reference for the engineering application of RK-Joints.

Abstract: In the paper the gymnasium was used to discuss the selection principle of computational domain, boundary conditions, meshing, turbulence model, the location of referred pressure, solved parameters, and the criterion of convergence during numerical simulation of flow-field around the building based on FLUENT software. Compared the results of numerical simulation and wind tunnel test, it is feasible to calculate the wind-pressure on the building surface based on the theory of computational fluid dynamics.