This paper presents the development of inspection strategies dedicated to the quality insurance of the wind turbine blade manufacturing process and in particular the inspection of the adhesive bondlines. Ultrasonic testing is recognized as a technique that can provide valuable information about the structure. Porosity, dry area and delamination can be detected and characterized in laminates. La...

This study presents an approach that uses the refined zigzag element, {2,2} RZE in conjunction with progressive failure criteria to predict the ultimate strength of composite laminates based on only ply-level strength properties. The methodology involves four major steps: (1) Determination of accurate stress and strain fields under complex loading conditions using {2,2} RZE -based finite elemen...

This article features a large statistical database on the tensile properties of natural fibre reinforced composite laminates. The data presented here corresponds to a comprehensive experimental testing program of several composite systems including: different material constituents (epoxy and vinyl ester resins; flax, jute and carbon fibres), different fibre configurations (short-fibre mats, uni...

1 2004 (1) References [1] M. Cho and S. Y. Rhee. Optimization of laminates with free edges under bounded uncertainty subject to extension, bending and twisting. International Journal of Solids and Structures, 41:227–245, 2004. [2] C. Lin and Y. Lee. Stacking sequence optimization of laminated composite structures using genetic algorithm with local improvement. Composite Structures, 63:339–345, ...

Abstract The FRP material plays a major role as strengthening in RC structural elements. It is popularly used to improve the load carrying capacity and stiffness elements by wrapping with sheets (combination of GFRP & CFRP). usefulness laminates external at both sides full vertical strips interval 100mm on beams studied.. In this experimental study nine reinforced concrete were cast that th...

in this paper, nonlinear behavior of composite steel plate shear wall systems, in which steel infill plate is strengthened by fiber reinforced polymer (frp) layers, are experimentally investigated. tests are designed to evaluate the effect of glass-frp layers, layers number of gfrp and orientation of gfrp layers on the stiffness, shear strength, cumulative dissipated energy and other seismic pa...

Abstract The use of terahertz time-domain spectroscopy (THz-TDS) for the nondestructive testing and evaluation (NDT&E) materials structural systems has attracted significant attention over past two decades due to its superior spatial resolution capabilities detecting characterizing defects damage in non-conducting materials. In this study, THz-TDS system is used detect, localize evaluate hi...

This paper presents new analytical model of asymmetric mixed-mode bending (MMB) specimen of adhesively bonded pultruded GFRP joints. An easily applicable relationship for the calculation of the strain energy release rate of the asymmetric MMB specimens is proposed based on the beam theory. The model is capable to analyze stacking sequence as well as various crack propagation paths. In the paper...

The impact damage response of balsa core sandwich composite plates with S2-glass/ epoxy reinforced facesheets is evaluated by impacting them with a spherical steel projectile at single impact locations. The impact damage can significantly reduce the structural integrity and load bearing capacity of a composite structure. Under high velocity impact loading, laminated composites experience signif...

In the present study, vibration of cylindrical laminates with different layers and angles were studied. In order to actuate and polarize in radial direction, a piezoelectric layer was located at outer surface of composite shell. Laminates were assumed long enough so that plane strain state analysis in 2D can be used properly. In order to satisfy the boundary conditions, variables in terms of Fo...