Papers by Keyword: Large Deformation

Abstract: The instability and dynamics behavior of a cantilevered thin-elastic plate with large deformation subjected to axial flow is studied numerically. The structural dynamics equation is discretized by isoparametric displacement-based finite, and the motion of a continuous fluid domain is governed by two-dimensional incompressible viscous Navier-Stokes equations, which discretized by finite volume method. The two-dimensional numerical model of two-way fluid-structure coupling is established combined with moving mesh technology, realizing the interaction of thin-elastic plate and axial fluid. Firstly, under given different flow velocity, the stability of limit-cycle oscillations has been studied through Hopf bifurcation, time trace, vibration responses. Secondly, the fluid domain features are analyzed qualitatively by separately comparing with vorticity under given different flow velocity, and cloud diagram of pressure and velocity are also analyzed at U=3.6m/s.

Abstract: Finite element analysis on the strength and stability with the full extension job is researched for some special truck crane. The different telescopic parts are connected by the slider, which can transfer load through mutual contact and deform. Stress concentration always appear with the traditional method, so the contact algorithm is vital to the simulation. The intensity and stability of the boom is simulated with finite element analysis with the degree coupling technology, the simulation results have significance for further optimal design of the boom.

Abstract: In this work, the influence of a rigid cylindrical inclusion on the elastic field in a transparent soft material is studied by an embedded-grating technique. The same experimental procedure was implemented on two specimens, a homogeneous bulk soft material and the same material containing a rigid cylindrical inhomogeneity. Under the indentation of a rigid wedge, two kinds of deformation sectors underneath the contacting boundary are observed from experimental results. Furthermore, the shape of the deformation sectors is horizontally expanded due to the inclusion. A local fluctuation of contact stresses between the soft matrix and rigid inclusion are discussed.

Abstract: In this research, both un-deformed or Lagrangian state and deformed or Eulerian state are used to derive for stability analysis and large deformation. By choosing the deformed radius of curvature and deformed angle of tangent slope as parameters, the governing equations of laminated curved beam under static loading are transformed into a set of equations in terms of angle of tangent slope. All the quantities of axial force, shear force, radial and tangential displacements of circular thin curved beam are expressed as functions of angle of tangent slope by using laminate theory. The buckling load and large deformation analytical solutions of circular thin curved beam under a pair of forces are presented as well.

Abstract: In the present study, nonlinear bending problem of functionally graded material (FGM) cantilever beams resting on a Winkler elastic foundation under distributed load are discussed. Based on the large deformation theory and considering the axial extension of the beam, the equilibrium equations with geometric nonlinearity of FGM beams subjected to distributed load are established. In the analysis, it is assumed that the material properties of the beam vary continuously as a power function of the thickness. By using shooting method, the nonlinear boundary-value problem is numerically solved as well as the non-linear bending characteristic curves of the deformed beam versus the load are presented. The effects of material gradient property and foundation stiffness parameter on the bending deformation of the beam are discussed in detail.

Abstract: Despite their ubiquity, the simulation of granular materials poses a continuing challenge in computational mechanics, as these materials can behave like solid, liquid and gas. In this paper, a recently developed version of the Particle Finite Element Method is applied for analyzing the behaviour of granular media under very large deformations. Both quasi-static and dynamic problems are considered. It is shown that this continuum approach is applicable to general large deformation problems of granular materials, including liquid-like flows.

Abstract: Gaoligong Mountain tunnel is the key project in the Dali-Ruili Railway. In order to optimize the design and guide construction, In-situ stress has been conducted in five boreholes using hydraulic fracturing method, the current shallow crustal in-situ stress state at the project area are obtained according to the measurements results, and deep in-situ stress is predicted using lateral pressure coefficient. The test results show that at depths ranging from 299-979m, the maximum horizontal principal stress is 5.33-30.12Mpa, the minimum horizontal principal stress is 4.94-23.11Mpa, the horizontal principal stress reach 30Mpa at maximum the depth of burial, indicating that the engineering stress filed is dominated by horizontal stress. Based on the In-situ stress data and different distinguish methods, rockburst and large deformation are predicted. The results show that In-situ stress magnitude in this area is classified as high level, and the direction of the maximum horizontal stress is NEE, In-situ stress orientation is conductive to stable of the tunnel. When the tunnel passes through the deep-burial and hard rock, the wall rock may happen rockburst; and the large deformation may happen when the tunnel pass through the weak rock. In order to avoid the disadvantage conditions, reasonable excavation method and safety support method should be adopted during tunnel excavating.

Abstract: The textile industry is represented not only by fashion (most popular area) but also textile material for industrial purposes. The very old use of textile materials is production of fabric bags. The deformation of such bag is the subject of computer modeling, what is the contents of the paper. The deformation of the 2D cloth layer, exposed to normal pressure, has the mathematical description in the form of the partial differential equation. The solution depends on the area, on which is searched, and on the boundary conditions. It is known only for planar circular area. The deformation of more complicated shapes (3D) must be found using computer simulations. The problem, discretized by finite element method, has the form of the system of algebraic equations. The description has non-linear character and brings a range of problems. The solution possibilities are described in the paper. Finally the solution of the 3D problem is shown.

Abstract: Mathematical model based on elasticity is not suitable for soft seam hydraulic fracturing mechanism study because its intensity is small, Poisson's ratio is relatively large, and its prone to plastic deformation. Based on plastic mechanics, the theory of large deformation and fracture mechanics theory, hydraulic fracturing of soft coal seam is divided into three phases, namely, coal bed compaction, fracture initiation and crack propagation from the view of the deformation mechanism, the occurring and developing mechanism. The initiation pressure of soft seams considered strain softening character after plastic deformation is obtained on the basis of above. The result shows that the initiation pressure is related to elastic modulus, Poisson's ratio, the angle of internal friction and residual strength. Elastic modulus is inversely proportional to the initiation pressure, the greater its value, the smaller the initiation pressure; but Poisson's ratio, the angle of internal friction and the residual strength and fracture initiation pressure is directly proportional relationship, the greater its value, since the smaller the crack pressure.

Abstract: The point of this study was to assess the progressive collapse resisting capacity of special steel moment frame structures and the behaviour of buildings which have different height when they are losing one of their exterior columns. Two buildings were considered for this research, 7-storiy and 12-storiy buildings. Corner column as well as one of the middle columns was removed to evaluate the importance and the effect of the location of removed column in structural response. General Services Administration (GSA) and Department of Defence (DoD) guidelines are considered for choosing the method of analysis. Nonlinear dynamic analysis procedures were carried out to investigate the behavior of structures. Thus, maximum vertical displacement in the point of column removal for each structure was measured. In addition, both buildings have cover plate connections which are cosidered to be rigid in modelling.