Top-hat hollow-section beams are widely used in passenger vehicle’s body-in-white structure because of their proper shape for the montage process and also crashworthiness advantages. Hollow section beams with top-hat cross-section are mostly employed in structures like B-pillar, rocker sill, and roof rail which are engaged in side impact collisions. In the present investigation, simplified top-hat beams are developed based on a conventional B-pillar with the aim of improving energy absorption characteristics. Reinforcements are conducted by employing fiber glass-epoxy composite material. Three types of reinforced beams are presented which are either improved by composite-laminating, or by installation of an extra composite-made internal r

The paper investigates the addition of Nano-Al2O3 powder (alumina, Average Particle Size: 20 nm) on the characteristics of the Medium Density Fibreboards (MDF) made by the forest fibers. Some important physical, mechanical and quasi-static properties of the panels were measured according to the standard test methods and apparatus. Different percentages of alumina powder (0, 1, 2, and 3 weight percentage (wt.) based on the solid content of resin) were used and panels were made in three thicknesses (5, 10 and 14 mm). The experiments showed that the resultant properties of the new composites were improved. The greatest increase in Modulus of Elasticity (MOE) was achieved when 1% wt. alumina was added to the samples. Addition of alumina up

The aim of this study is to investigate the improvement in energy absorption of a top-hat profile hollow-section beam by attaching different shapes of internal reinforcements. The base structure of the beam was first considered as a hat shape structure which was jointed to a flat plate using spot-welds. Three types of sheet metal reinforcements were formed and attached inside the beam’s structure. Then, they were tested experimentally under quasi-static three-point bending loading condition. Also, these reinforced structures were numerically simulated using LS-DYNA explicit code. After the numerical simulation is validated using experimental data, some new cross-sections were proposed for reinforcing component, and the specim

This paper investigates the behavior of grid stiffened composite panel (GSCP) subjected to transverse loading by analytical and experimental approach. An improved analytical model is proposed on the basis of smeared method to compute an equivalent stiffness matrix for the isogrid lattice of the GSCP. Hence, the panel can be considered as a laminate with different layers of specific stiffness. In this manner, the global deformation of GSCPs is studied in three types of transverse loading: three-point bending, quasi-static indentation and low-velocity impact. The model is verified by the same experimental tests on some fabricated glass/epoxy GSCPs. The results indicate the good compatibility of analytical model with experiments. Moreover, ene

In this paper, low velocity impact on nano-beam using couple stress theory was investigated. Modified couple stress theory was utilized to capture size-dependent effects. Hamilton’s principle was employed to derive governing equations and boundary conditions and then general solution was proposed. The solutions validity was confirmed by comparing present results with that of the literature. Comparing the results shows the present theory is capable to predict low velocity dynamic behavior with acceptable accuracy. The results show as mass ratio increased, natural frequencies decreased and then trend to a constant value. This limit is higher for second and third natural frequencies. Also, the natural frequencies increased when characteristi

In the present study, static behavior of short hybrid laminate beams was investigated using a unified zig-zag theory (ZZT) containing various beam theories as special cases. This theory satisfies transverse shear stresses continuity in the interface of layers via piece-wise continuous arbitrary shape functions. The principle of virtual work was employed to derive unified equilibrium equations and suitable boundary conditions. The present theory obviates the need for stress recovery for continuous transverse stresses. A general solution was presented to analyse high transversely anisotropic laminates under several kinds of transverse loads (general lateral, sinusoidal and point load) and non-linear thermal loads. The validity of this model i

This paper details the experimental testing and numerical simulation of crushing performance of laminated composite tube under impact loading. Composite tube is modeled as multiple layers of shell elements and chamfered trigger is accounted for by sequentially reducing the length of the layers. The simulation is performed using a Continuum Damage Mechanics material model for representing the intralaminar behavior in which damage activates according to LaRC03-04 failure criteria and propagates according to a set of linear and bi-linear softening laws. Mesh objectivity is accounted for by incorporating crack band law and regularizing dissipated energy by element characteristic length. Interlaminar fractures are modeled using Tiebreak contact