PURPOSE This study evaluated whether a Class II restoration in a flowable resin composite has to be placed prior to (open-sandwich technique) or after (closed-sandwich technique) construction of the interproximal wall in the centripetal build-up technique in order to reduce microleakage. METHODS AND MATERIALS Thirty non-carious molars were selected and randomly divided into two groups (n = 15...

the steel shear wall and composite steel plate shear wall is introduced in recent three decade and is considered and is spread rapidly. composite steel plate shear wall which is made of a layer of thin steel sheet with coating of reinforced concrete in one or both sides of steel palate is considered a third generation of resistance shear walls against lateral loads that in addition to increasin...

The bending behavior of composites sandwich plates with multi-layered laminated face sheets has been investigated, using a new four-nodded rectangular finite element formulation based on a layer-wise theory. Both, first order and higher-order shear deformation; theories are used in order to model the face sheets and the core, respectively. Unlike any other layer-wise theory, the number of degre...

The propagation of Lamb-like waves in sandwich plates made of anisotropic and viscoelastic material layers is studied. A semi-analytical model is described and used for predicting the dispersion curves (phase velocity, energy velocity, and complex wave-number) and the through-thickness distribution fields (displacement, stress, and energy flow). Guided modes propagating along a test-sandwich pl...

the present paper investigates the advantages of a new class of composite grid structures over conventional grids. thus far, a known grid structure such as orthogrid or isogrid has been used as an orthotropic layer with at most in-plane anisotropy. the present laminated grid is composed of various numbers of thin composite grid layers. the stiffness of the structure can be adjusted by choosing ...

There is a growing interest in developing non-destructive damage detection methods for damage assessment of composite structures, especially in the aerospace and marine industries. Although damage detection of composite laminates has been widely investigated, little work has been carried out on sandwich composite configurations. A technique using the Lipschitz exponent, which is estimated by wa...

abstract: in this paper, the results of experimental and numerical simulation of low velocity impact process have been carried out to investigate energy absorption of composite sandwich panels with 3d woven fabrics of glass fibers and epoxy resin. for this purpose, diagrams of force-displacement of the quasi-static and quasi-dynamic impact tests were studied. for the finite element simulation, ...

We present a novel method for fabricating carbon fiber composite sandwich panels with lattice core construction by means of electrical discharge machining (EDM). First, flattop corrugated carbon fiber composite cores were fabricated by a hot press molding method. Then, two composite face sheets were bonded to each corrugated core to create precursor sandwich panels. These panels were transforme...

In this paper an experimental-numerical approach is presented to tackle the vibro-acoustic characterization of composite sandwich structures. A novel experimental setup allows for fast and comprehensive understanding of the NVH behaviour of composite sandwich panels. This information can then be further exploited in numerical model updating and design tools for optimized solutions. Experimental...