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Tai-yan Kam - One of the best experts on this subject based on the ideXlab platform.

  • Quasi-static buckling and first-Ply Failure loads of shear web reinforced glass-fabric composite wind blades
    Composite Structures, 2017
    Co-Authors: Tai-yan Kam, C.y. Huang
    Abstract:

    Abstract A procedure is proposed to analyze the structural Failure of a composite wind blade subjected to quasi-static loads. The structural Failure of a wind blade under extreme wind loads which can be treated as quasi-static loads is an important issue to be tackled when assessing the reliability of a wind turbine. In the proposed structural Failure analysis procedure, the geometrically nonlinear finite element (FE) method together with several phenomenological Failure criteria is used to investigate the possible Failure modes such as incipient buckling, interfacial debonding, and first-Ply Failure of the blade via an incremental loading approach. The Failure loads and locations associated with the possible Failure modes for a number of small wind blades with different structural configurations are determined to study the appropriateness of the Failure criteria. Static tests of several small glass-fabric composite wind blades were conducted to validate the suitability of the proposed procedure. It has been shown that the experimentally and theoretically predicted Failure processes of the wind blades are in good agreement. The applications of the proposed procedure are demonstrated by means of a numerical example in which the Failure process of a wind blade under quasi-static wind loads is simulated.

  • Experimental and theoretical predictions of first-Ply Failure strength of laminated composite plates
    International Journal of Solids and Structures, 1999
    Co-Authors: Tai-yan Kam, Feng-min Lai
    Abstract:

    Abstract Experimental and theoretical methods are presented to study the first-Ply Failure strength of laminated composite plates under different loading conditions. An acoustic emission technique is used to measure the energy released in the plates during the Failure process. The first-Ply Failure strength of the plates is then identified via the energy vs load diagrams which are constructed on the basis of the measured acoustic emissions. A finite element analysis, which is constructed on the basis of the layerwise linear displacement theory, and the Tsai–Wu Failure criterion are used to predict the first-Ply Failure strength of the plates. The comparison between the experimental and theoretical results shows good agreement.

  • EVALUATION OF BUCKLING AND FIRST-Ply Failure PROBABILITIES OF COMPOSITE LAMINATES
    International Journal of Solids and Structures, 1998
    Co-Authors: S. C. Lin, Tai-yan Kam, K. H. Chu
    Abstract:

    Abstract A procedure for Failure probability evaluation of composite laminates subjected to inplane loads is proposed. The material properties, fiber angles and layer thicknesses of the laminates are treated as random variables in the reliability analysis. The statistics of first-Ply Failure loads and buckling strengths of the laminates are determined via the stochastic finite element method. The Failure probabilities of the laminates which are susceptible to buckling and first-Ply Failure are computed using the statistics obtained in the stochastic finite element analysis. The feasibility and accuracy of the present approach are validated using the results obtained via the Monte-Carlo method. A number of examples of reliability analysis of composite laminates subject to in-plane loads are given to illustrate the applications of the procedure.

  • First-Ply Failure strength of laminated composite pressure vessels
    Composite Structures, 1997
    Co-Authors: Tai-yan Kam, Y.w. Liu, F.t. Lee
    Abstract:

    Strengths of laminated composite pressure vessels are studied via both analytical and experimental approaches. Experimental techniques are presented to determine the first-Ply Failure and burst strengths of laminated composite pressure vessels with different lamination arrangements. Different analytical methods, together with various Failure criteria, are used to predict the first-Ply Failure strengths of the laminated pressure vessels. The accuracy of the theoretical prediction of first-Ply Failure strength is verified by the test data. The suitability of the Failure criteria, as well as the limitations of the analytical methods are discussed.

  • Reliability formulation for composite laminates subjected to first-Ply Failure
    Composite Structures, 1997
    Co-Authors: Tai-yan Kam, E.s. Chang
    Abstract:

    Methods formulated on the basis of the concept of first-Ply Failure and the structural reliability theory are presented for the reliability analysis of laminated composite plates. In the reliability formulation, an appropriate phenomenological Failure criterion is used to establish the limit state equation of the laminated composite plates, and different numerical techniques are employed to evaluate the reliability of the plates. Experimental investigations of lamina strengths and first-Ply Failure loads of laminated composite plates were performed. Baseline probability distributions of lamina strength parameters constructed from the test data are used to study the reliability of the laminated plates. The accuracy of the proposed models in reliability assessment of the laminated plates are verified by the experimental results on first-Ply Failure load distributions.

Dipankar Chakravorty - One of the best experts on this subject based on the ideXlab platform.

  • a finite element prediction of first Ply Failure and delamination in composite conoidal shells using geometric nonlinearity
    Sadhana-academy Proceedings in Engineering Sciences, 2020
    Co-Authors: Kaustav Bakshi, Dipankar Chakravorty
    Abstract:

    A review of the existing literature shows that there is only one research report available on Failure of laminated composite conoidal shells using geometrically nonlinear strains. Thus, this paper aims for a detailed study on first Ply Failure and delamination predictions of laminated composite conoidal shell using von-Karman nonlinearity and first order shear deformation theory. The nonlinear equations are solved by Newton–Raphson iterative method. The Failure loads of the shell are furnished for two different boundary conditions and stacking orders of cross and angle-Ply laminations. The Failure locations on the shell surface and Failure modes/tendencies are also reported. This study finds that the SSCC boundary and 0°/90°/0° lamination should be selected by practicing engineers to achieve the maximum load carrying capacity of the conoid out of the two edge conditions considered here. Factor of safety values applicable on the Failure loads are also suggested keeping due weightage to serviceability criterion.

  • First Ply Failure Study of Laminated Composite Conoidal Shells Using Geometrically Nonlinear Formulation
    Recent Advances in Theoretical Applied Computational and Experimental Mechanics, 2020
    Co-Authors: Kaustav Bakshi, Dipankar Chakravorty
    Abstract:

    The literature clearly indicates that the Failure of laminated composite plates have been studied in detail while composite shell structures have received limited attention. Though few recent papers reported first Ply Failure of conoidal shells in order to apPly these shell forms confidently in industrial applications, the Failure investigations need to be continued for different parametric variations keeping the industrial requirements in mind. This study attempts to fill the lacuna. An isoparametric finite element code considering geometrically nonlinear strains and constant shear deformation along the thickness direction of the shell is proposed to study Failure initiation in uniformly loaded laminated conoidal shell roofs having two adjacent boundaries simPly supported and other two adjacent edges clamped. Moreover, Failure locations and modes or tendencies of Failure are also reported. The results are studied for varying stacking orders and laminations. This study recommends that the practicing engineers must adopt 30°/−30°/30° laminate to maximize load-carrying capacity of the shell for the edge condition taken up here.

  • Nonlinear first Ply Failure analysis of composite skewed hypar shells using FEM
    Structural Engineering and Mechanics, 2018
    Co-Authors: Arghya Ghosh, Dipankar Chakravorty
    Abstract:

    This paper uses the finite element method (FEM) considering geometrically nonlinear strains to study the first Ply Failure of laminated composite skewed hypar shell roofs through well-established Failure criteria along with the serviceability criterion of deflection. Apart from validating the approach through solution of benchmark problems, skewed hypars with different practical parametric variations are studied for Failure loads and tendencies. First Ply Failure zones are also identified to suggest design and non-destructive monitoring guidelines to the practising engineers. Recommendation tables regarding the design approaches to be adopted in specific cases and factor of safety values needed to be imposed on first Ply Failure load values for varying shell curvatures are also suggested in this paper. Providing practical inputs to design engineers is the main achievement of the present study.

  • First Ply Failure analysis of laminated composite thin hypar shells using nonlinear finite element approach
    Thin-Walled Structures, 2018
    Co-Authors: Arghya Ghosh, Dipankar Chakravorty
    Abstract:

    Abstract In this paper the nonlinear finite element approach is used to solve the problems of first Ply Failure of laminated composite skewed hypar thin shell roofs. The geometrically nonlinear strains terms are incorporated in the present finite element code which is validated through solution of the problems solved and published by earlier researchers. The first Ply Failure loads of the industrially popular, aesthetically appealing hypar shells are studied meticulously for varying aspect ratios and thicknesses for clamped boundary condition. The paper gives specific recommendations regarding choice of linear and nonlinear approaches for obtaining Failure loads in different specific cases.

  • Geometrically Nonlinear First Ply Failure Loads of Laminated Composite Conoidal Shells
    Procedia Engineering, 2017
    Co-Authors: Kaustav Bakshi, Dipankar Chakravorty
    Abstract:

    Abstract Review of the existing literature on shells indicates that first Ply Failure of laminated conoidal shells, particularly using geometric nonlinearity was not reported by any researcher. Conoidal shell is an aesthetically appealing, stiff, easy to cast surface which is popular to cover large column free open spaces found in shopping malls, auditoriums and aircraft hangers. Lightweight laminated composites are often used to fabricate them. Laminated composite is weak in transverse shear and may initiate Failure at any inner lamina. Such latent damages progress gradually within the laminate and lead to sudden catastrophic collapse under service condition. Thus, the first Ply Failure load has to be known to a practicing engineer. This paper reports first Ply Failure of conoidal shells using geometrically nonlinear isoparametric finite element formulation. The results are presented for different parametric variations and the study concludes with set of meaningful engineering design guidelines keepingalso the serviceability criterion in mind.

S. K. Satsangi - One of the best experts on this subject based on the ideXlab platform.

  • First Ply Failure analysis of stiffened panels – a finite element approach
    Composite Structures, 2001
    Co-Authors: B. G. Prusty, Chaitali Ray, S. K. Satsangi
    Abstract:

    A first-Ply Failure analysis method has been developed for predicting the Failure load on the laminated composite stiffened panels under various loading conditions. The present finite element formulation is generalised to analyse both laminated bare/stiffened plate and shell panels elegantly. Eight noded isoparametric quadratic elements for shell and three noded curved beam elements for the stiffener are used for the analysis of stiffened panel. The stiffness matrix of the stiffener is computed independently and then transferred to that of the shell. The formulation eliminates the restriction on the location and orientation of the stiffener within the shell element. Several prominent Failure theories have been considered in the present work for the prediction of Failure load. The results obtained by the present formulation have been compared with those available in literature and some parametric study has also been performed on the basis of variety in shell geometry.

  • First Ply Failure Analysis of Laminated Panels under Transverse Loading
    Journal of Reinforced Plastics and Composites, 2001
    Co-Authors: B. G. Prusty, S. K. Satsangi, Chaitali Ray
    Abstract:

    The present investigation deals with the Failure analysis of the weakest Ply in a laminated composite plate or shell using the method of finite elements. The objective of the study is to detect the stress level at the stage of initiation of damage in the composite panels. An eight noded isoparametric quadratic shell element has been used apPlying first order shear deformation theory. The elegance of the present formulation lies in the capability of analysing plate as well as shallow and deep shell using a single formulation. Various Failure criteria have been studied to predict the load when the weakest lamina fails under transverse static load. The investigation has been made on various plates and shells having varying lamination schemes. Published results on first Ply Failure analysis of laminated plates are scanty, however the results on laminated shells are not available in the literature. A number of problems on laminated plates have been solved and the results are compared with those available in th...

  • first Ply Failure analysis of stiffened panels a finite element approach
    Composite Structures, 2001
    Co-Authors: B. G. Prusty, Chaitali Ray, S. K. Satsangi
    Abstract:

    A first-Ply Failure analysis method has been developed for predicting the Failure load on the laminated composite stiffened panels under various loading conditions. The present finite element formulation is generalised to analyse both laminated bare/stiffened plate and shell panels elegantly. Eight noded isoparametric quadratic elements for shell and three noded curved beam elements for the stiffener are used for the analysis of stiffened panel. The stiffness matrix of the stiffener is computed independently and then transferred to that of the shell. The formulation eliminates the restriction on the location and orientation of the stiffener within the shell element. Several prominent Failure theories have been considered in the present work for the prediction of Failure load. The results obtained by the present formulation have been compared with those available in literature and some parametric study has also been performed on the basis of variety in shell geometry.

  • Laminated Stiffened Plate-A First Ply Failure Analysis
    Journal of Reinforced Plastics and Composites, 1999
    Co-Authors: Chaitali Ray, S. K. Satsangi
    Abstract:

    A first Ply Failure analysis of composite stiffened plates has been presented using the finite element method. A new scheme has been formulated to model stiffened composite plates. The plate element has been formulated using an eight noded isoparametric quadratic plate bending element. A three noded isoparametric beam element has been used to formulate the stiffener element. The stiffness matrix of the stiffener element has been developed independently and then the stiffness matrix is transferred to that of the plate element. This technique eliminates the restriction on the orientation of the stiffener within the plate element. The formulation has been validated by analysing a number of problems. The results obtained are compared with those available in published literature.

Chaitali Ray - One of the best experts on this subject based on the ideXlab platform.

  • Effect of hybridisation in laminated composites on the first Ply Failure behaviour: Experimental and numerical studies
    International Journal of Mechanical Sciences, 2019
    Co-Authors: Dhiraj Biswas, Chaitali Ray
    Abstract:

    Abstract First Ply Failure analysis of hybrid laminated plate panels subjected to transversely applied static load is carried out and presented in this article. Hybrid laminates are fabricated in the laboratory as a combination of carbon and glass fabrics along with epoxy resin for this purpose. Strength and elastic properties of epoxy based laminates with carbon fibre (CFRP) and glass fibre (GFRP) are determined experimentally according to ASTM standard. Various multilayered hybrid laminates (HFRP) and GFRP laminates having all edges fixed boundary condition are tested under transverse static load. An improved eight noded quadratic isoparametric plate bending element based on refined higher order zigzag theory (HRZT) has been developed in the present study to evaluate the interlaminar stresses of multilayered composite laminates. The warping function has been considered in the displacement field to formulate a C° continuous plate bending element. The transverse shear stresses are computed in a simplified manner using the three dimensional differential equations of stress equilibrium. The first Ply Failure load is determined within linear and elastic range. The correctness and competence of the present finite element model is verified by comparing the solutions with relevant published data and also experimental outcome. The comparison between HFRP and GFRP laminates in terms of Failure load has been made to identify the effectiveness of hybridisation.

  • First Ply Failure Analysis of Laminated Panels under Transverse Loading
    Journal of Reinforced Plastics and Composites, 2001
    Co-Authors: B. G. Prusty, S. K. Satsangi, Chaitali Ray
    Abstract:

    The present investigation deals with the Failure analysis of the weakest Ply in a laminated composite plate or shell using the method of finite elements. The objective of the study is to detect the stress level at the stage of initiation of damage in the composite panels. An eight noded isoparametric quadratic shell element has been used apPlying first order shear deformation theory. The elegance of the present formulation lies in the capability of analysing plate as well as shallow and deep shell using a single formulation. Various Failure criteria have been studied to predict the load when the weakest lamina fails under transverse static load. The investigation has been made on various plates and shells having varying lamination schemes. Published results on first Ply Failure analysis of laminated plates are scanty, however the results on laminated shells are not available in the literature. A number of problems on laminated plates have been solved and the results are compared with those available in th...

  • First Ply Failure analysis of stiffened panels – a finite element approach
    Composite Structures, 2001
    Co-Authors: B. G. Prusty, Chaitali Ray, S. K. Satsangi
    Abstract:

    A first-Ply Failure analysis method has been developed for predicting the Failure load on the laminated composite stiffened panels under various loading conditions. The present finite element formulation is generalised to analyse both laminated bare/stiffened plate and shell panels elegantly. Eight noded isoparametric quadratic elements for shell and three noded curved beam elements for the stiffener are used for the analysis of stiffened panel. The stiffness matrix of the stiffener is computed independently and then transferred to that of the shell. The formulation eliminates the restriction on the location and orientation of the stiffener within the shell element. Several prominent Failure theories have been considered in the present work for the prediction of Failure load. The results obtained by the present formulation have been compared with those available in literature and some parametric study has also been performed on the basis of variety in shell geometry.

  • first Ply Failure analysis of stiffened panels a finite element approach
    Composite Structures, 2001
    Co-Authors: B. G. Prusty, Chaitali Ray, S. K. Satsangi
    Abstract:

    A first-Ply Failure analysis method has been developed for predicting the Failure load on the laminated composite stiffened panels under various loading conditions. The present finite element formulation is generalised to analyse both laminated bare/stiffened plate and shell panels elegantly. Eight noded isoparametric quadratic elements for shell and three noded curved beam elements for the stiffener are used for the analysis of stiffened panel. The stiffness matrix of the stiffener is computed independently and then transferred to that of the shell. The formulation eliminates the restriction on the location and orientation of the stiffener within the shell element. Several prominent Failure theories have been considered in the present work for the prediction of Failure load. The results obtained by the present formulation have been compared with those available in literature and some parametric study has also been performed on the basis of variety in shell geometry.

  • Laminated Stiffened Plate-A First Ply Failure Analysis
    Journal of Reinforced Plastics and Composites, 1999
    Co-Authors: Chaitali Ray, S. K. Satsangi
    Abstract:

    A first Ply Failure analysis of composite stiffened plates has been presented using the finite element method. A new scheme has been formulated to model stiffened composite plates. The plate element has been formulated using an eight noded isoparametric quadratic plate bending element. A three noded isoparametric beam element has been used to formulate the stiffener element. The stiffness matrix of the stiffener element has been developed independently and then the stiffness matrix is transferred to that of the plate element. This technique eliminates the restriction on the orientation of the stiffener within the plate element. The formulation has been validated by analysing a number of problems. The results obtained are compared with those available in published literature.

B. G. Prusty - One of the best experts on this subject based on the ideXlab platform.

  • First Ply Failure Analysis of Laminated Panels under Transverse Loading
    Journal of Reinforced Plastics and Composites, 2001
    Co-Authors: B. G. Prusty, S. K. Satsangi, Chaitali Ray
    Abstract:

    The present investigation deals with the Failure analysis of the weakest Ply in a laminated composite plate or shell using the method of finite elements. The objective of the study is to detect the stress level at the stage of initiation of damage in the composite panels. An eight noded isoparametric quadratic shell element has been used apPlying first order shear deformation theory. The elegance of the present formulation lies in the capability of analysing plate as well as shallow and deep shell using a single formulation. Various Failure criteria have been studied to predict the load when the weakest lamina fails under transverse static load. The investigation has been made on various plates and shells having varying lamination schemes. Published results on first Ply Failure analysis of laminated plates are scanty, however the results on laminated shells are not available in the literature. A number of problems on laminated plates have been solved and the results are compared with those available in th...

  • First Ply Failure analysis of stiffened panels – a finite element approach
    Composite Structures, 2001
    Co-Authors: B. G. Prusty, Chaitali Ray, S. K. Satsangi
    Abstract:

    A first-Ply Failure analysis method has been developed for predicting the Failure load on the laminated composite stiffened panels under various loading conditions. The present finite element formulation is generalised to analyse both laminated bare/stiffened plate and shell panels elegantly. Eight noded isoparametric quadratic elements for shell and three noded curved beam elements for the stiffener are used for the analysis of stiffened panel. The stiffness matrix of the stiffener is computed independently and then transferred to that of the shell. The formulation eliminates the restriction on the location and orientation of the stiffener within the shell element. Several prominent Failure theories have been considered in the present work for the prediction of Failure load. The results obtained by the present formulation have been compared with those available in literature and some parametric study has also been performed on the basis of variety in shell geometry.

  • first Ply Failure analysis of stiffened panels a finite element approach
    Composite Structures, 2001
    Co-Authors: B. G. Prusty, Chaitali Ray, S. K. Satsangi
    Abstract:

    A first-Ply Failure analysis method has been developed for predicting the Failure load on the laminated composite stiffened panels under various loading conditions. The present finite element formulation is generalised to analyse both laminated bare/stiffened plate and shell panels elegantly. Eight noded isoparametric quadratic elements for shell and three noded curved beam elements for the stiffener are used for the analysis of stiffened panel. The stiffness matrix of the stiffener is computed independently and then transferred to that of the shell. The formulation eliminates the restriction on the location and orientation of the stiffener within the shell element. Several prominent Failure theories have been considered in the present work for the prediction of Failure load. The results obtained by the present formulation have been compared with those available in literature and some parametric study has also been performed on the basis of variety in shell geometry.