The Experts below are selected from a list of 471 Experts worldwide ranked by ideXlab platform
Raphael T. Haftka - One of the best experts on this subject based on the ideXlab platform.
-
Optimization with non-homogeneous failure criteria like Tsai–Wu for composite laminates
Structural and Multidisciplinary Optimization, 2006Co-Authors: Albert A. Groenwold, Raphael T. HaftkaAbstract:In designing composite laminates, minimization of a suitable failure Criterion is sometimes selected as the objective function. However, for non-homogeneous criteria, e.g., the Tsai–Wu Criterion, this objective function will not maximize the failure load, when it is carried at a load which is different from the failure load. We suggest that the use of a safety factor for the objective function is more appropriate for maximizing for the faiure load. In fact we show losses of more than 40% in the load carrying capacity even when the load carrying capacity of the optimal laminate is 75% of the applied load.
Peggi L. Clouston - One of the best experts on this subject based on the ideXlab platform.
-
A stochastic plasticity approach to strength modeling of strand-based wood composites
Composites Science and Technology, 2002Co-Authors: Peggi L. CloustonAbstract:A 3 dimensional stochastic finite element technique is presented herein for simulating the nonlinear behaviour of strand-based wood composites with strands of varying grain-angle. The approach is based on the constitutive properties of the individual strands to study the effects of varying strand characteristics (such as species or geometry) on the performance of the member. The constitutive properties of the strands are found empirically and are subsequently used in a 3 dimensional finite element program. The program is formulated in a probabilistic manner using random variable material properties as input. The constitutive model incorporates classic plasticity theory whereby anisotropic hardening and eventual failure of the material is established by the Tsai– Wu Criterion with an associated flow rule. Failure is marked by an upper bound surface whereupon either perfect plasticity (i.e. ductile behavior) or an abrupt loss of strength and stiffness (i.e. brittle behavior) ensues. The ability of this technique to reproduce experimental findings for the stress–strain curves of angle-ply laminates in tension, compression as well as 3 point bending is validated. # 2002 Elsevier Science Ltd. All rights reserved.
-
Computational Modeling of Strand-Based Wood Composites
Journal of Engineering Mechanics-asce, 2001Co-Authors: Peggi L. CloustonAbstract:A nonlinear stochastic model has been formulated to simulate the stress-strain behavior of strand-based wood composites based on the constitutive properties of the wood strands. Prediction models of this type save time and money in the development of wood composites by computationally gauging the effects of varying raw material characteristics with limited fabrication and testing of the full-scale product. The proposed model uses a stochastic-based materially nonlinear finite-element code with extended capacity to perform Monte Carlo simulations to predict the stress-strain behavior of [±15]s and [±30]s angle-ply laminates in tension and compression. The nonlinear constitutive behavior of the wood strands is characterized within the framework of rate-independent theory of orthotropic plasticity, where the plastic flow rule is in accordance with the Tsai-Wu Criterion. Shear strength and stiffness of the strands, as well as the interaction parameter of the Tsai-Wu Criterion have been estimated through a min...
V. A. Romashchenko - One of the best experts on this subject based on the ideXlab platform.
-
Strength assessment for composite and metal-composite cylinders under pulse loading. Part 2. Numerical evaluation of strength for multilayer cylinders of finite length under internal explosion
Strength of Materials, 2012Co-Authors: V. A. Romashchenko, Yu. N. Babich, E. V. BakhtinaAbstract:Using a numerical experiment method, the authors have solved a problem of optimization for a three-layer metal-composite cylinder of finite length, which is loaded with axisymmetric internal explosion. The optimization consists in finding the best layer thickness ratio and reinforcement configuration for the cylinder’s anisotropic composite part in order to provide the maximum strength margin by Tsai–Wu Criterion for the fixed overall dimensions of the cylinder and the relative explosive charge mass. The use of an elastoplastic isotropic steel 20 for the internal layer is demonstrated to significantly improve the metal-composite cylinder strength owing, in particular, to plastic yielding, in comparison to a purely composite cylinder. The use of high-strength steels with a high yield stress is not advisable. The application of all-metal shells is impractical from the standpoint of materials consumption – they are too heavy.
-
Strength assessment for composite and metal-composite cylinders under pulse loading. Part 1. Rules of choosing various strength criteria for anisotropic material and comparative analysis of such criteria
Strength of Materials, 2012Co-Authors: V. A. RomashchenkoAbstract:The author formulates the rules one should follow when choosing strength criteria for a composite. A comparative analysis of Ashkenazi and Tsai–Wu strength criteria is performed for a specific orthotropic material, and the criteria are shown to agree with each other. An update of the Tsai–Wu Criterion is put forward for composites that have uniform tension and compression strength.
Albert A. Groenwold - One of the best experts on this subject based on the ideXlab platform.
-
Optimization with non-homogeneous failure criteria like Tsai–Wu for composite laminates
Structural and Multidisciplinary Optimization, 2006Co-Authors: Albert A. Groenwold, Raphael T. HaftkaAbstract:In designing composite laminates, minimization of a suitable failure Criterion is sometimes selected as the objective function. However, for non-homogeneous criteria, e.g., the Tsai–Wu Criterion, this objective function will not maximize the failure load, when it is carried at a load which is different from the failure load. We suggest that the use of a safety factor for the objective function is more appropriate for maximizing for the faiure load. In fact we show losses of more than 40% in the load carrying capacity even when the load carrying capacity of the optimal laminate is 75% of the applied load.
Mamidala Ramulu - One of the best experts on this subject based on the ideXlab platform.
-
Failure Analysis of a Fibrous Composite Half-Space Subjected to Uniform Surface Line Load
Volume 13: Processing and Engineering Applications of Novel Materials, 2020Co-Authors: Suhasini Gururaja, Mamidala RamuluAbstract:Uni-Directional Fiber-Reinforced Plastic (UD-FRP) laminates have been modeled previously as an equivalent quasi-homogeneous monoclinic half-space subjected to an inclined line load on the surface using Lekhnitskii’s formulation simulating the orthogonal edge trimming loads in UD-FRPs. In continuation, failure analysis of the aforementioned composite half-space has been carried out in the present investigation based on Tsai-Wu Criterion. In particular, the failure behavior of the half-space laminate with respect to the fiber orientation, load inclination angle and spatial coordinates has been examined in detail. The motivation behind such a study lies in correlating the failure behavior of the half-space laminate with the damage progression observed during orthogonal edge trimming experiments. The present work strives at identifying this relationship and in the process, understanding the physics of orthogonal cutting mechanisms in UD-FRP laminates.Copyright © 2007 by ASME
-
Failure analysis of a fibrous composite half-space subjected to uniform surface line load
Journal of Engineering Materials and Technology-transactions of The Asme, 2009Co-Authors: Suhasini Gururaja, Mamidala RamuluAbstract:Unidirectional fiber-reinforced plastic (UD-FRP) laminates have been modeled previously as an equivalent quasihomogeneous monoclinic half-space subjected to an inclined line load on the surface using Lekhnitskii's formulation simulating the orthogonal edge trimming loads in UD-FRPs. In continuation, failure analysis of the aforementioned composite half-space has been carried out in the present investigation based on Tsai-Wu Criterion. In particular, the failure behavior of the half-space laminate with respect to the fiber orientation, load inclination angle, and spatial coordinates has been examined in detail. The motivation behind such a study lies in correlating the failure behavior of the half-space laminate with the machining damage observed during orthogonal edge trimming experiments. The present work strives at identifying this relationship and, in the process, understanding the physics of orthogonal cutting of UD-FRP laminates.
