Papers by Keyword: Sandwich Plate

Abstract: The properties of the base metal, weld and joint of CCS-B material for sandwich plate used in ship structurewasconfirmedthrough the tensile test,which provided the data parameters for the finite element simulation;The three points bending test for laser-weldedI-coresandwich plate was simulated by ABAQUS,and two kinds of models were establishedby considering and without considering weld material properties, which load-displacement curve shows that the influence of the weld material properties is larger to plates stiffness, but less to bearing capacity; For the model whichwas considered the weld material property, the development of plastic zone and the measurement of stress state show:In the elastic stage, the localposition yield in the junction zone between the web and upper and lower weld; In the plastic stage,the large areayield in the panel and the web of T-joint zone; The mapping relationship from the stress state to macroscopic deformation shows that both of the panel and the web occur S shape deformation and the whole web plate occur inclination deformation.

Abstract: Underwater impact and explosion are the main methods that destroy the warships, it cause attention of countries with marine power. The all metal laser welded sandwich panels has the higher stiffness and better mechanical behavior, and be used to protect for warships against impact. This paper analyzed the displacement of sandwich panel on light impact object with different impact velocity , which show that: (1) The top plate penetrate at the impact velocity of 185m/s, then the bottom plate is penetrate when the impact velocity approaches to 275m/s. (2) The displacement of top plate is confined to the scope of 60mm along x-axis and 40mm along Y-axis from the impacting point at a high impact velocity, the failure mode of sandwich panel is serious partial destruction and obvious shear failure.

Abstract: A nonlinear dynamic finite element method based on ANSYS/LS-DYNA is used to simulate the physical process of a bullet penetrating circular sandwich plate at a speed of about 400 m/s. In the simulation, Lagrange algorithm, Johnson-Cook and Crushable-foam constitutive model are choosed. Energy time history curve, impact force time history curve, Von-Mises stress nephogram and displacement nephogram are obtained. At the same time, stress time history curve of the maximum stress element and displacement time history curve of the maximum displacement node are obtained. Compared with the non-sandwich plate, it is found that the use of sandwich plate can reduce the total mass, inner plate stress and displacement, and can protect inner plate well.

Abstract: Treat the upper plate and lower plate of ribbed hollow floor as the surfaces of sandwich panel, and the ribbed hollow layer as the central layer of sandwich panel; consider the bending stiffness of the surfaces and transverse shear deformation of the central layer; use Hoff laminated theory; based on the same stiffness principle; establish sandwich panel structure model of hollow floor; Derive partial differential equations of cast-in-place reinforced concrete two-way ribbed and thin-walled hollow floor under vertical uniform load and present the analytic solution of the equations with two opposite clamped edges and others simply supported edges. Analyze the mechanical properties of hollow floor. The results are very close to the results of using finite element method.

Abstract: Based on Reissner’s sandwich plate theory, the critical globlal buckling equation of sandwich plate with ribs is deduced by energy method under simple support boundary conditions. And the critical buckling solution is obtained and discussed here. Afterwards a rectangular sandwich plate with steel faceplate and polyurthane core is taken as an example. The influence on critical global buckling stress with different inertia moments in rectangular sandwich plates are discussed. simularly the effect of the lengh ratio of two sides and the thickness of rectangular sandwich plate are also studied.

Abstract: In this paper, the penetration effect of a rhombic fragment penetrating sandwich in an oblique incidence with 30º impact angle at the velocity of 300 m•s^-1, 350 m•s^-1, 400 m•s^-1, 450 m•s^-1, 500 m•s^-1 and 600 m•s^-1 is simulated by LS-DYNA. The dynamic response and the damage patterns of sandwich plate and the movement rules of the rhombic fragment are acquired. The ratio of energy loss and the maximum resultant acceleration of the rhombic fragment are compared with that of the spherical respectively.

Abstract: In this paper, the damage patterns of the hexagonal aluminum honeycomb sandwich plate subjected to normal and oblique impact by spherical, cylindrical and cubic fragments at different velocities are simulated using LS-DYNA code. The damage patterns of the sandwich plate and the energy loss ratio of fragment are acquired. In normal and oblique impact for different shapes of the fragment, the damage patterns of the sandwich plate include the plastic deformation, the fracture and the perforation of the face sheet and the tearing of the core or the combination of them. The curve of energy loss ratio waves with the velocity of fragment. And the peak point at the curve of energy loss ratio versus the velocity of fragment denotes the limit velocity of fragment. Furthermore, the energy loss ratios of fragments in oblique impact at the velocity of 500 m•s-1 with the angle of impact of 5°, 10°, 15° and 20° are obtained. The results denote that a fragment with large ratio of length to diameter is easy to perforate the sandwich plate both in normal and oblique impact.

Abstract: Nowadays Shape Memory Alloys (SMAs) are used as actuators in many applications such as aerospace structures. In sandwich structures, the SMA wires or plates are used in the skins for shape control of the structure or vibration damping. In this paper, bending behavior of sandwich plates with embedded SMA wires in their skins is studied. 3D finite element method is used for construction and analysis of the sandwich plate with a flexible core and two stiff skins. Some important points such as continuity conditions of the displacements, satisfaction of interlaminar transverse shear stresses, the conditions of zero transverse shear stresses on the upper and lower surfaces and in-plane and transverse flexibility of soft core are considered for accurate modeling and analysis of sandwich structures. Solution for bending analysis of sandwich plates under various transverse loads are presented and the effect of many parameters such as plate dimensions, loading conditions, material properties of core, skins and SMA wires are studied. Comparison of the present results in special case with those of the three-dimensional theory of elasticity and some plate theories confirms the accuracy of the proposed model.

Abstract: Sandwich plates have been extensively used in many engineering applications such as automotive and aerospace. In the present paper, an accurate finite element model is presented for bending analysis of soft-core rectangular sandwich plates. The sandwich plate is composed of three layers: top and bottom skins and core layer. The core is assumed as a soft orthotropic material and skins are assumed generally unequal laminated composites. Finite element model of the problem has been constructed in the ANSYS 11.0 standard code area. Continuity conditions of transverse shear stresses at the interfaces are satisfied as well as the conditions of zero transverse shear stresses on the upper and lower surfaces of plate. Also transverse flexibility and transverse normal strain and stress of core are considered. The effect of geometrical parameters of the sandwich plate are studied. Comparison of the present results with those of plate theories confirms the accuracy of the proposed model.

Abstract: In the present paper, an accurate 3D finite element model is presented for bucking analysis of soft-core rectangular sandwich plates. The sandwich plate is composed of three layers: top and bottom skins and core layer. Finite element model of the problem has been constructed in the ANSYS 11.0 standard code area. The effect of geometrical parameters of the sandwich plate is studied. Comparison of the present results with those of plate theories confirms the accuracy of the proposed model. The overall buckling loads calculated by FE model are higher than that of the accurate results and the maximum discrepancy is less than 10 percent.