Papers by Keyword: Relative Slip

Abstract: Based on the push-out test of the improved PBL shear connector, a finite element modal was established. In the FEA software of ANSYS, element type of Solid65 was adopted to simulate concrete; element type of Solid45 was adopted to simulate perforated rebar and steel plate, and element type of Conta173 and element type of Targe170 were adopted to simulate the interaction between perforated rebar and concrete, corrugated perforated plates and concrete. From the calculation of finite element modal, carrying capacity of the shear connector and the relative slip between steel plate and concrete were got. By comparing, the result of experiment is well with the result of calculation. Furthermore, the finite element modal is used to simulate mechianial properties of double row holes PBL shear connector. From the result of calculation, it can be concluded that the carrying capacity of double row holes shear connector is higher than the single row hole shear connector.

Abstract: The encased concrete composite beams were modeled and calculated using nonlinear finite element method, considering relative slipping of concrete and steel. on that basis, the load-deformation curve and the relative slip distribution of the models between concrete and steel along the longitudinal beam bottom were analyzed. Then the results were compared with existed test data; in addition, numerical simulations in 4 groups with cotters in different separation distances were performed, the deformation feature and relative slip distribution rule of concrete and steel in different shear connection degree were discussed.

Abstract: Steel and concrete composite structures are widely used in bridge engineering, for it can fully utilize the compression property of concrete and tensile behavior of the steel. However, the coupled behavior of shrinkage and creep exist in concrete. The creep behavior is dependent on the initial stress, while shrinkage is not. The shrinkage and creep of the concrete have a significant influence on the internal force and deformation and it may cause the cracking or even the failure of the structure. Nowadays, precast concrete slab is widely adopted in the composite bridges to reduce the effect of shrinkage and creep. Storage time is a critical parameter for the precast concrete slab to reach the best economic benefit and mechanical behavior of the structure. Therefore, in this paper, the finite element model of Xinshiji Bridge with the consideration of the relative slip between the steel and concrete was established to investigate the influence of loading age of the concrete on the mechanical behavior of the composite bridge, and the optimal storage time was determined.

Abstract: By mean of potential energy various principles,the governing differential equations of the steel and concrete composite girder in considering relative slips between steel girders and concrete slabs and shear lag effects of the flanges and the concrete slab are derived. The equations are solved by Galerkin method. It is shown from the calculating example that the proposed method not only is easy to calculate, but also has high convergent speed

Abstract: According to deforming properties of the structure in the action of symmetry loads and the assumption to the displacement functions of the equivalent composite box beam, the total potential energy of the structure is obtained. Based on the spline finite point method, the stiffness equations are deduced, which could be used to determine the approximate solution of the through composite truss under the action of double-lines symmetry loads in considering the relative slip between longitudinal beams and concrete slabs on the deck system, the vertical deformation of transverse beams and the shear lag effect of concrete slabs. The mechanics behavior of the thorough composite truss is studied by means of a calculated example.

Abstract: Numerical analysis by influence function method (IFM) is demonstrated in this study in order to investigate the fretting wear problems on the secondary side of the steam generator, caused by flow induced vibration. Two-dimensional numerical contact model is developed in terms of Cauchy integral equation. The distributions of normal pressures, shear stresses and displacement fields are derived between two contact bodies which have similar elastic properties. The work rate model is adopted to find the wear amounts between two materials. The results are compared with the solutions by finite element analyses, which validates the application of the present method to fretting wear problems.

Abstract: Mechanical breakdown often comes from the fatigue in many structural parts and nuclear power plants. Among the fatigue phenomenon, especially fretting fatigue occurs in mechanical joints showing small relative movements between contact surfaces. Although the research was developed for one hundred years, occurrence mechanism is not clearly identified yet. INCOLOY alloy 800 is a iron-nickel-chromium alloy having excellent resistance to many corrosive aqueous media and high-temperature atmospheres. This alloy is used extensively in the nuclear power plants industry, the chemical industry, the heat-treating industry and the electronic industry. In this paper, the effect of fretting damage on fatigue behavior for INCOLOY alloy 800 was studied. Also, various kinds of mechanical tests such as tension and plain fatigue tests are performed. Fretting fatigue tests were carried out with flat-flat contact configuration using a bridge type contact pad and plate type specimen. Through these experiments, it is found that the fretting fatigue strength decreased about 50% compared to the plain fatigue strength. In fretting fatigue, the oblique micro-cracks at an earlier stage are initiated. These results can be used as basic data in a structural integrity evaluation of heat and corrosion resisting alloy considering fretting damages.

Abstract: The thermo-mechanical simulation of Friction Stir Welding focuses the interest of the welding scientific and technical community. However, literature reporting material flow modeling is rather poor. The present work is based on the model developed by Heurtier [2004] and aims at improving this thermo-fluid simulation developed by means of fluid mechanics numerical and analytical velocity fields combined together. These various velocity fields are investigated separately and especially according to the power dissipated during the flow. Boundary conditions are considered through a new approach based on the kinematic analysis of the thread of the pin. An equilibrium is established between the vertical motion of the bulk material dragged in the depth of the metal sheet, and its partial circulation around the pin. The analyses of the obtained velocity fields enable the understanding of the welded zone asymmetry and highlights the bulk material mixing between the welded coupons in the depth of the sheet. A regression is performed on the relative sliding velocity of the aluminium according to the surface of the tool: shoulder and pin. Two dimension flow lines in the depth of the metal sheet are then obtained and successfully compared with the results obtained by Colegrove (2004) [1].