The Experts below are selected from a list of 123537 Experts worldwide ranked by ideXlab platform
John Montesano - One of the best experts on this subject based on the ideXlab platform.
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the effect of staggered matrix crack induced delamination growth on the mechanical properties of cross ply laminates
2021Co-Authors: Sepideh Rezaei Jafari, Amin Farrokhabadi, John MontesanoAbstract:Abstract Matrix cracking in composite laminates is a common sub-Critical Damage mechanism that forms under thermomechanical loading and may induce delamination , which is a prevailing Critical Damage mechanism. Previous studies have considered induced delamination stemming from a symmetric pattern of matrix cracks despite observations revealing matrix crack patterns are staggered. In this study, delamination cracks induced from staggered matrix cracks in [90 n/0m/90n]s cross-ply laminates is investigated analytically for the first time. A new energy-based analytical model is developed within the framework of classical lamination theory , where distinct zones along the induced delamination cracks are defined in the unit cell and a crack closure technique is employed. The laminate stiffness and strain energy release rate (ERR) are predicted for increasing induced delamination crack length. The analytical results were in excellent agreement with that of a finite element analysis (FEA) of the unit cell, demonstrating the accuracy and robustness of the developed model.
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assessing progressive failure in long wind turbine blades under quasi static and cyclic loads
2018Co-Authors: John Montesano, Yangjie Zuo, Chandra Veer SinghAbstract:Predicting progressive failure and consequential loss in the load-bearing capability of large-scale composite wind blades is vital for accurately assessing their service life and maintenance. A physics-based multi-scale Damage model describing progressive ply cracking and joint adhesive debonding in blades under both quasi-static and cyclic loading is presented. The complete structure of the blade was considered including the shell-spar adhesive joint and shell-root adhesive joint. For quasi-static loading, the geometrical transition region of the blade was observed as the Critical ply crack Damage region, which was in agreement with previous experimental results. The matrix micro-cracking Damage was mainly caused by high gale wind speeds, and adhesive debonding ultimately initiated at the shell-spar joint. The blade tip deflection increased nonlinearly with increasing wind speeds, reaching 29.0% of the blade length at 19 m/s. For cyclic loading, sub-Critical Damage grew along the length of the blade with increasing cycles, gradually increasing the normal and shear stresses in the joint adhesive layer as the crack density increased, eventually leading to local shell-spar adhesive debonding. The simulation methodology presented here will be useful for assessing the durability and increasing the safety and accuracy of service life prediction of large-scale blade structures.
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development of a physics based multi scale progressive Damage model for assessing the durability of wind turbine blades
2016Co-Authors: John Montesano, Hao Chu, Chandra Veer SinghAbstract:Abstract A physics-based multi-scale progressive Damage model was developed for predicting the durability of wind turbine blade structures. Computational micromechanics was coupled within a continuum Damage mechanics (CDM) framework, and implemented through a user-defined subroutine within commercial finite element software, for evaluating sub-Critical Damage evolution and stiffness degradation of the blade structure. The study is the first step in developing an accurate prediction model for composite wind turbines that accounts for the multi-scale nature of Damage in rotor blades. The quasi-static and fatigue simulation results demonstrate the ability of the model to predict the evolution of Damage in the Critical regions of the blade structure, which is an important contribution and essential for increasing the accuracy of Damage tolerance analyses and for certification of composite structures. A parametric study of blade geometric parameters also revealed a correlation with Damage evolution, providing valuable insight for optimization of blade designs.
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non destructive assessment of the fatigue strength and Damage progression of satin woven fiber reinforced polymer matrix composites
2015Co-Authors: John Montesano, Zouheir Fawaz, Habiba BougheraraAbstract:Abstract The aim of this study is to utilize infrared thermography to assess the Critical Damage states, and to capture the evolving Damage processes, of 5HS and 8HS woven carbon fiber/epoxy composites subjected to uniaxial in-plane tensile quasi-static and fatigue loading. Quasi-static test results revealed that the dominant Damage mechanisms were matrix cracks contained within the weft yarns, which initiated at the thermally-detected material thermoelastic limit and were confirmed through SEM observations. An established thermographic technique was also used to confirm the existence of a high cycle fatigue limit, which may in fact be a characteristic of all fabric reinforced polymeric composites. Temperature profiles captured during cyclic testing directly correlated with corresponding stiffness degradation profiles, providing support for thermography as an accurate fatigue Damage metric. The infrared camera was able to detect the evolution of weft yarn cracking during the initial stage, as well as the initiation and growth of interply delamination cracking during the final stage of three-stage cyclic Damage evolution. The reported results and observations provide an important step in the validation of thermography as a powerful non-destructive tool for assessing the development of Damage, as well as predicting the Critical Damage states of fiber reinforced polymeric composite materials.
Chandra Veer Singh - One of the best experts on this subject based on the ideXlab platform.
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assessing progressive failure in long wind turbine blades under quasi static and cyclic loads
2018Co-Authors: John Montesano, Yangjie Zuo, Chandra Veer SinghAbstract:Predicting progressive failure and consequential loss in the load-bearing capability of large-scale composite wind blades is vital for accurately assessing their service life and maintenance. A physics-based multi-scale Damage model describing progressive ply cracking and joint adhesive debonding in blades under both quasi-static and cyclic loading is presented. The complete structure of the blade was considered including the shell-spar adhesive joint and shell-root adhesive joint. For quasi-static loading, the geometrical transition region of the blade was observed as the Critical ply crack Damage region, which was in agreement with previous experimental results. The matrix micro-cracking Damage was mainly caused by high gale wind speeds, and adhesive debonding ultimately initiated at the shell-spar joint. The blade tip deflection increased nonlinearly with increasing wind speeds, reaching 29.0% of the blade length at 19 m/s. For cyclic loading, sub-Critical Damage grew along the length of the blade with increasing cycles, gradually increasing the normal and shear stresses in the joint adhesive layer as the crack density increased, eventually leading to local shell-spar adhesive debonding. The simulation methodology presented here will be useful for assessing the durability and increasing the safety and accuracy of service life prediction of large-scale blade structures.
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development of a physics based multi scale progressive Damage model for assessing the durability of wind turbine blades
2016Co-Authors: John Montesano, Hao Chu, Chandra Veer SinghAbstract:Abstract A physics-based multi-scale progressive Damage model was developed for predicting the durability of wind turbine blade structures. Computational micromechanics was coupled within a continuum Damage mechanics (CDM) framework, and implemented through a user-defined subroutine within commercial finite element software, for evaluating sub-Critical Damage evolution and stiffness degradation of the blade structure. The study is the first step in developing an accurate prediction model for composite wind turbines that accounts for the multi-scale nature of Damage in rotor blades. The quasi-static and fatigue simulation results demonstrate the ability of the model to predict the evolution of Damage in the Critical regions of the blade structure, which is an important contribution and essential for increasing the accuracy of Damage tolerance analyses and for certification of composite structures. A parametric study of blade geometric parameters also revealed a correlation with Damage evolution, providing valuable insight for optimization of blade designs.
Christophe Bouvet - One of the best experts on this subject based on the ideXlab platform.
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Prediction of the ultimate strength of quasi-isotropic TP-based laminates structures from tensile and compressive fracture toughness at high temperature
2019Co-Authors: Benoît Vieille, Juan-daniel Pujols Gonzalez, Christophe BouvetAbstract:This paper is intended to test the capacity of a simple model based on fracture mechanics concepts to predict the ultimate strength of notched hybrid carbon and glass fibers woven-ply reinforced PolyEther Ether Ketone (PEEK) thermoplastic (TP) quasi-isotropic (QI) laminates under different temperature conditions. In such materials, translaminar failure is the primary failure mode driven by the breakage of 0° and 45° oriented fibers in tension as well as the formation of kink-band in compression. Single-Edge-Notched Bending (SENB), Open-Hole-Tensile (OHT) and Open-Hole-Compression (OHC) specimens have been conducted at room temperature (RT) and at a temperature higher than the glass transition temperature (Tg). The Critical Damage Growth model derived from the Average Stress Criterion and Linear Elastic Fracture Mechanics (LEFM) have been applied to open-hole specimens to determine the Critical Damage zone from which the fracture toughness in tension (0° and 45° fibers breakage) KIc-tension and in compression (kink-band formation) KIc_comp. are estimated. In Single Edge Notched Bending (SENB) specimens experience simultaneous tension/compression. From the estimation of KIc-tension and KIc_comp., the ultimate strength of SENB specimens can be predicted. LEFM equations combined with the Critical fracture toughness in tension give relatively accurate results, suggesting that failure is driven by fibers bundles breakage in tension.
Yangjie Zuo - One of the best experts on this subject based on the ideXlab platform.
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assessing progressive failure in long wind turbine blades under quasi static and cyclic loads
2018Co-Authors: John Montesano, Yangjie Zuo, Chandra Veer SinghAbstract:Predicting progressive failure and consequential loss in the load-bearing capability of large-scale composite wind blades is vital for accurately assessing their service life and maintenance. A physics-based multi-scale Damage model describing progressive ply cracking and joint adhesive debonding in blades under both quasi-static and cyclic loading is presented. The complete structure of the blade was considered including the shell-spar adhesive joint and shell-root adhesive joint. For quasi-static loading, the geometrical transition region of the blade was observed as the Critical ply crack Damage region, which was in agreement with previous experimental results. The matrix micro-cracking Damage was mainly caused by high gale wind speeds, and adhesive debonding ultimately initiated at the shell-spar joint. The blade tip deflection increased nonlinearly with increasing wind speeds, reaching 29.0% of the blade length at 19 m/s. For cyclic loading, sub-Critical Damage grew along the length of the blade with increasing cycles, gradually increasing the normal and shear stresses in the joint adhesive layer as the crack density increased, eventually leading to local shell-spar adhesive debonding. The simulation methodology presented here will be useful for assessing the durability and increasing the safety and accuracy of service life prediction of large-scale blade structures.
Benoît Vieille - One of the best experts on this subject based on the ideXlab platform.
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Prediction of the ultimate strength of quasi-isotropic TP-based laminates structures from tensile and compressive fracture toughness at high temperature
2019Co-Authors: Benoît Vieille, Juan-daniel Pujols Gonzalez, Christophe BouvetAbstract:This paper is intended to test the capacity of a simple model based on fracture mechanics concepts to predict the ultimate strength of notched hybrid carbon and glass fibers woven-ply reinforced PolyEther Ether Ketone (PEEK) thermoplastic (TP) quasi-isotropic (QI) laminates under different temperature conditions. In such materials, translaminar failure is the primary failure mode driven by the breakage of 0° and 45° oriented fibers in tension as well as the formation of kink-band in compression. Single-Edge-Notched Bending (SENB), Open-Hole-Tensile (OHT) and Open-Hole-Compression (OHC) specimens have been conducted at room temperature (RT) and at a temperature higher than the glass transition temperature (Tg). The Critical Damage Growth model derived from the Average Stress Criterion and Linear Elastic Fracture Mechanics (LEFM) have been applied to open-hole specimens to determine the Critical Damage zone from which the fracture toughness in tension (0° and 45° fibers breakage) KIc-tension and in compression (kink-band formation) KIc_comp. are estimated. In Single Edge Notched Bending (SENB) specimens experience simultaneous tension/compression. From the estimation of KIc-tension and KIc_comp., the ultimate strength of SENB specimens can be predicted. LEFM equations combined with the Critical fracture toughness in tension give relatively accurate results, suggesting that failure is driven by fibers bundles breakage in tension.