scholarly journals First Ply Failure Behaviour of Laminated Composite Skew Plate under Concentrated Load

2020 ◽  
Vol 8 (6) ◽  
pp. 28-33
Author(s):  
Ravi Kumar ◽  
Dona Chatterjee ◽  
Arghya Ghosh ◽  
Dipankar Chakravorty
Keyword(s):  
Laminated Composite ◽  
Concentrated Load ◽  
Failure Behaviour ◽  
Skew Plate

Усиление внутреннего слоя многослойного композита базальтопластиком в виде сотовой структуры

2021 ◽  
Vol 27 (2) ◽  
pp. 205-216
Author(s):  
Г. П. Пономарева ◽  
◽  
И. М. Попова ◽  
О. М. Сладков ◽  
М. В. Пономарев ◽  
...  
Keyword(s):  
Mechanical Characteristics ◽  
Laminated Composite ◽  
Middle Layer ◽  
Epoxy Compound ◽  
Reaction Mass ◽  
Relative Deformation ◽  
Concentrated Load ◽  
Liquid Reaction ◽  
Constant Rate ◽  
Physical And Mechanical Characteristics

In our studies we present a multilayer structure consisting of outer layers of two-ply basalt composed of basalt fabric impregnated with an epoxy compound and an inner layer of polyurethane reinforced with basalt, having the same composition, formed in conjugate hexagonal prisms, and forming a cellular framework. The main part describes the technological sequence of obtaining basalt face layers, basalt hexagonal cellular frame, and filling it with a liquid reaction mass of rigid polyurethane system. The formation of a single multilayer composite structure is shown. We also present the results of the experimental research of strength of a laminated composite and its inner layer without facing layers when tested for static bending with concentrated load increasing at a constant rate and compression testing up to 10% of relative deformation. It describes the effect of the size of hexagonal prismatic cells of the frame on the physical and mechanical characteristics of the middle layer. The reduction of the cell size results in the increase of the composite strength. The dependence of the composite density on the size of the cells of the basalt frame has been studied.

scholarly journals Prediction of Progressive Failure Behaviour of Composite Skewed Hypar Shells Using Finite Element Method

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Arghya Ghosh ◽  
Dipankar Chakravorty
Keyword(s):  
Finite Element ◽  
Shear Failure ◽  
Progressive Failure ◽  
Laminated Composite ◽  
Practical Significance ◽  
Plane Stress Condition ◽  
Failure Behaviour ◽  
Failure Loads ◽  
Element Approach ◽  
Failure Theories

Progressive failure behaviour of laminated composite skewed hypar shells is investigated in this paper through finite element approach. For composite materials which are weak in transverse shear, failure may initiate at any inner lamina or interface and may remain undetected and unattended to. Such latent damages may progress gradually and lead to a sudden total ply failure. An iterative method is adopted using the various failure theories to predict the first ply failure load. After the first ply failure, the stiffness of the failed element is totally discarded from the laminate and the remaining laminate is considered for further analysis. The developed finite element code is validated through solution of a benchmark problem. Numerical experiments are carried out to obtain the first ply and progressive failure of simply supported hypar shells under transverse distributed load. While obtaining the failure loads, the shell is considered to be under plane stress condition and in linear elastic range. Results are studied meticulously to extract a set of conclusions of practical significance regarding the failure characteristics of composite hypar shells.

Buckling of laminated composite skew plate using FEM and machine learning methods

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Bharat Bhushan Mishra ◽  
Ajay Kumar ◽  
Pijush Samui ◽  
Thendiyath Roshni
Keyword(s):  
Machine Learning ◽  
Transverse Shear ◽  
Deformation Theory ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Fe Model ◽  
Third Order ◽  
Content Type ◽  
Buckling Strength ◽  
Skew Plate

Purpose The purpose of this paper is to attempt the buckling analysis of a laminated composite skew plate using the C0 finite element (FE) model based on higher-order shear deformation theory (HSDT) in conjunction with minimax probability machine regression (MPMR) and multivariate adaptive regression spline (MARS). Design/methodology/approach HSDT considers the third-order variation of in-plane displacements which eliminates the use of shear correction factor owing to realistic parabolic transverse shear stresses across the thickness coordinate. At the top and bottom of the plate, zero transverse shear stress condition is imposed. C0 FE model based on HSDT is developed and coded in formula translation (FORTRAN). FE model is validated and found efficient to create new results. MPMR and MARS models are coded in MATLAB. Using skew angle (α), stacking sequence (Ai) and buckling strength (Y) as input parameters, a regression problem is formulated using MPMR and MARS to predict the buckling strength of laminated composite skew plates. Findings The results of the MPMR and MARS models are in good agreement with the FE model result. MPMR is a better tool than MARS to analyze the buckling problem. Research limitations/implications The present work considers the linear behavior of the laminated composite skew plate. Originality/value To the authors’ best of knowledge, there is no work in the literature on the buckling analysis of a laminated composite skew plate using C0 FE formulation based on third-order shear deformation theory in conjunction with MPMR and MARS. These machine-learning techniques increase efficiency, reduce the computational time and reduce the cost of analysis. Further, an equation is generated with the MARS model via which the buckling strength of the laminated composite skew plate can be predicted with ease and simplicity.

Dynamic analysis of a composite beam subjected to a moving load

2009 ◽  
Vol 223 (7) ◽  
pp. 1543-1554 ◽  
Author(s):  
M J Rezvani ◽  
Karami M Khorramabadi
Keyword(s):  
Dynamic Analysis ◽  
Composite Beam ◽  
Moving Load ◽  
Equations Of Motion ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Bending Moment ◽  
Axial Direction ◽  
Transformation Method ◽  
Concentrated Load

In this article, the dynamic analysis of an infinite Timoshenko beam made of a laminated composite located on a generalized Pasternak viscoelastic foundation is studied. The beam is subjected to a moving concentrated load. It is assumed that the mechanical properties of the beam change in the direction of the beam thickness but remain constant in the axial direction. Closed-form steady-state solutions, based on the first-order shear deformation theory, are developed. By selection of an appropriate displacement field for the composite beam, and using the principle of total minimum potential energy, the governing partial differential equations of motion are obtained and solved through a complex infinite Fourier transformation method. The results are introduced in terms of deflection, bending moment, shear force, and stress. In addition, the effects of stiffness, shear layer viscosity coefficients of foundation, velocity of the moving load, number of layers, and various angles of layers over the beam response are studied. For some specific cases, the results are compared with those presented in some other published papers, with which good agreements are observed.

A TEM study of the interface between organic matrix and aragonite in a biological hard tissue, nacre

1992 ◽  
Vol 50 (2) ◽  
pp. 1024-1025
Author(s):  
Jun Liu ◽  
Katie E. Gunnison ◽  
Mehmet Sarikaya ◽  
Ilhan A. Aksay
Keyword(s):  
Mechanical Properties ◽  
Ion Beam ◽  
Laminated Composite ◽  
Organic Matrix ◽  
Pearl Oyster ◽  
Interfacial Structure ◽  
Interfacial Region ◽  
Thin Sections ◽  
Organic Layers ◽  
Transmission Electron

The interfacial structure between the organic and inorganic phases in biological hard tissues plays an important role in controlling the growth and the mechanical properties of these materials. The objective of this work was to investigate these interfaces in nacre by transmission electron microscopy. The nacreous section of several different seashells -- abalone, pearl oyster, and nautilus -- were studied. Nacre is a laminated composite material consisting of CaCO3 platelets (constituting > 90 vol.% of the overall composite) separated by a thin organic matrix. Nacre is of interest to biomimetics because of its highly ordered structure and a good combination of mechanical properties. In this study, electron transparent thin sections were prepared by a low-temperature ion-beam milling procedure and by ultramicrotomy. To reveal structures in the organic layers as well as in the interfacial region, samples were further subjected to chemical fixation and labeling, or chemical etching. All experiments were performed with a Philips 430T TEM/STEM at 300 keV with a liquid Nitrogen sample holder.

Sign in / Sign up

Export Citation Format

Share Document