Applied Mechanics and Materials Vols. 204-208

Abstract: The purpose of this work is to reveal the dynamical behavior of the nonlinear PHI-four equation, which is an interesting and very useful model in particle physics and mathematical physics. As a result, travelling wave solutions of nonlinear PHI-four equation are formally derived by employing hyperbolic tangent method in this paper. This paper shows that hyperbolic tangent method can be a powerful tool in obtaining evolution solutions of nonlinear system.

Abstract: A new interface element method was proposed to calculate the strain energy release rates(SERR) based on the virtual crack closure technique (VCCT). A Lagrange multiplier was introduced between the node pair at crack tip to obtain the internal forces. Then from the VCCT, the SERR was solved by using the forces and displacements near the crack tip. Examples for stationary cracks under the two typical cases are given. Meanwhile, the relationship curves between crack energy release rate and the length of crack, plate depths were plotted respectively.The example shows that the interface element used to calculate the SERR is simple, efficient, and highly accurate in analysis of 2D crack growth problems, and without requiring the special singularity element or collapsed element at crack tip.

Abstract: Bend channel is common seen in inland waterways. Due to the complex flow conditions, it’s often of great difficulty for ship maneuvering. To improve navigation conditions, usually the regulation is needed. In this paper, a 3D flow simulation model and ship maneuvering model are coupled. Based on the simulation results, the navigation conditions in Yiyang-Lulintan waterway project are evaluated. The simulation based evaluation provides a scientific basis and guidance for regulation projects in bend channel.

Abstract: In this paper, the dynamics of a van der pol model with delay are considered. It is shown that the asymptotic behavior depends crucially on the time delay parameter. By regarded the delay as a bifurcation parameter, we are particularly interested in the study of the Hopf bifurcation problem. The length of delay which preserves the stability of the equilibrium is calculated. Some numerical simulations for justifying the analytical findings are included.

Abstract: This paper puts forward that we can make glass fiber enhanced detaching-free template by using GRC composite materials, steel wire and other materials.In the construction,concrete beam and template form "Template /concrete" composite structure, which can make GRC template as a permanent structure bearing the stress together with concrete beam. Through the contrast test analysis and research of different treatments composite beams ,we can know the mechanical behavior and cooperative working performance of different composite beams.

Abstract: Abnormal pre-stretching of aluminum alloy thick-plate is simulated by using Marc FEM software to obtain the stress distribution of the plate under non-uniform clamping condition and material macroscopic deficiency. By analyzing the distribution contours, stress distributing characteristics of the pre-stretched thick-plate and their effects to rolling yield of thick plates under several typical cases are classified and summarized. Moreover, solving measures and advices are presented to reduce the negative effects.

Abstract: The two-degrees-of-freedom of vortex-induced vibration of circular cylinders is numerically simulated with the software ANSYS/CFX. The VIV characteristic, in the two different conditions (A/D=0.07 and A/D=1.0), is analyzed. When A/D is around 0.07, the amplitude ratio of the cylinder’s VIV between in-line and cross-flow direction in the lock-in is lower than that in the lock-out. The in-line frequency is twice of that in cross-flow direction in the lock-out, but in the lock-in, it is the same as that in cross-flow direction and the same as that of lift force. When A/D is around 1.0, the amplitude ratio of the VIV between in-line and cross-flow in the lock-in is obviously larger than that in the lock-out. Both in the lock-in and in the lock-out, the in-line frequency is twice of that in cross-flow direction.

Abstract: The behavior of CFRP-PCPs composite rebars on tensile test was studied. Experimental results showed that using CFRP-PCP composite rebars as reinforcement utilizes high strength of FRP effectively, reducing the reinforcement ratio and consequently the cost while simultaneously satisfying structural requirements. Tension stiffening in CFRP-PCPs composite rebars is significant when higher concrete strength and higher prestressing level are applied.

Abstract: The mechanics properties of CFRP-PCPs composite rebars under uniaxial load was studied by experiment. The results showed that the application of a reasonable amount of prestress to the prisms can limit service load deflections and crack width to acceptable levels, using CFRP-PCP composite rebars as reinforcement utilizes high strength of FRP effectively, reducing the reinforcement ratio and consequently the cost while simultaneously satisfying structural requirements.

Abstract: This paper proposed a new high-speed deformable trimaran based on DTMB5415, and discussed its advantages and applications. We computed the hydrodynamic performance with CFD method and analyzed the wave-making interference and resistance performance for eight different arrangements of this trimaran. The results show an optimal layout for this high-speed deformable trimaran, which can decrease the resistance of per unit displacement mass about 32%.