Postbuckling and failure analysis of layered composite panels

Abstract

This work consideres the buckling and postbuckling behaviour of axially compressed layered composite panels including initial failure analysis. For determination stresses in layered composite panels Finite Element Method (FEM) used. A series of experiments were conducted to verify the FEA-results, but also to address the stability and strength of the composite structure. Combining a geometric nonlinear finite element analysis (FEA) based on the von Karman theory and High Order Shear Deformation Theory (HOST) are used to study the first-ply failure behavior as well as the postbuckling behavior of laminated type composite panels. For this purpose and for the investigation of the failure responses improved 4-node layered shell finite elements are used. The finite element formulation is based on the third order shear deformation theory with four-node shell finite elements having eight degres of freedom per node. A simple method is proposed to predict buckling loads and the post-buckling behaviour together with initial failure analysis of layered composite panels. The experiments carried out on SCHRENK system. Comparisons between numerical and experimental results show quite a good agreement.

The Minor Influence of Calcium Doped Phosphate Tungsten Bronze on the Briggs-Rauscher Reaction Dynamics

“…From Figure 3., it can be underlined that the dependence of oscillatory period length from added mass of phosphate tungsten bronze is linear. Whereas, obtained dependence follows the saturation kinetics because the addition of 0,07 g of phosphate tungsten bronze comes into saturation [16]. Obtained linear dependence till the mass of added phosphate tungsten bronze of 0,05 g can be used as a calibration diagram [16].…”

“…Whereas, obtained dependence follows the saturation kinetics because the addition of 0,07 g of phosphate tungsten bronze comes into saturation [16]. Obtained linear dependence till the mass of added phosphate tungsten bronze of 0,05 g can be used as a calibration diagram [16]. From Figure 4, it can be seen that increase in the mass of calcium doped phosphate tungsten bron-ze doesn't lead to significant decrease in oscillation time of BR reaction, but it leads to significant decrease in oscillation amplitude.…”

“…This is a completely new approach to material testing, whereby the changes in oscillatory dynamics, in the presence of various bronzes, are followed and compared, in order to obtain information about the properties of the materials themselves. Recently, we examined the influence of lithium doped phosphate tungsten bronze and phosphate tungsten bronze [16], and this paper represents a continuation of the study and examines the effect of calcium doped phosphate tungsten bronze on the dynamics of the BR oscillatory reaction.…”

Effects of gelcoat thickness on mechanical properties of woven glass/polyester laminated composite

“…Hence it can be verified that a failure between the plies is matrix failure. The study of Maksimović [16] stated that four basic modes of failure that occur in laminate composite structures are: matrix cracking, fiber-matrix shear failure, fiber failure and delamination. Khelifa and Al-Shukri [17] argued that failure of laminas at ± 45° and 0° / 90° is due to matrix failure in the direction of the fiber, whereas for the unidirectional lamina at 0°, the failure is due to fiber breakages.…”

Modal damping ratio of symmetric laminate composite under the effect of attached mass using experimental design

“…With regard to the vibration behaviour of the composite structures, many studies were carried out to control and determine the dynamic characteristics of those materials. So, several authors have performed vibration analysis of laminated composite under various conditions of reinforcement and configuration [1][2][3][4][5][6][7].…”