Faculty Publications

Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736

Publications by NITK Faculty

Browse

Has files: NoSubject: search.filters.subject.Stress analysis

Search Results

Now showing 1 - 10 of 28
  • No Thumbnail Available
    Item
  • No Thumbnail Available
    Item
    Higher order refined computational model with 12 degrees of freedom for the stress analysis of antisymmetric angle-ply plates - analytical solutions
    (2007) Swaminathan, K.; Patil, S.S.
    Analytical formulations and solutions for the stress analysis of simply supported antisymmetric angle-ply composite and sandwich plates hitherto not reported in the literature based on a higher order refined computational model with twelve degrees of freedom already reported in the literature are presented. The theoretical model presented herein incorporates laminate deformations which account for the effects of transverse shear deformation, transverse normal strain/stress and a nonlinear variation of in-plane displacements with respect to the thickness coordinate thus modelling the warping of transverse cross sections more accurately and eliminating the need for shear correction coefficients. In addition, two higher order computational models, one with nine and the other with five degrees of freedom already available in the literature are also considered for comparison. The equations of equilibrium are obtained using Principle of Minimum Potential Energy (PMPE). Solutions are obtained in closed form using Navier's technique by solving the boundary value problem. Accuracy of the theoretical formulations and the solution method is first ascertained by comparing the results with that already available in the literature. After establishing the accuracy of the solutions, numerical results with real properties using all the computational models are presented for the stress analysis of multilayer antisymmetric angle-ply composite and sandwich plates, which will serve as a benchmark for future investigations. © 2006.
  • No Thumbnail Available
    Item
    Compression testing of Ti-6Al-4V in the temperature range of 303-873 K
    (2008) Srinivasan, K.; Venugopal, P.
    Compression testing of Ti-6Al-4V alloy has been carried out at temperatures between 303 K to 873 K. To prevent embrittlement due to atmospheric oxygen and nitrogen, the samples were given a glass coating, which also acts as a lubricant simultaneously. Dynamic Strain Aging was observed to occur in the temperature range of 600 K to 800 K. Below 600 K stresses were high. Warm working has to be done above 800 K but below 1163 K (0.6 Tm where Tm = 1940 K) which is the recrystallization temperature. Based on these conclusions, warm extrusion has been successfully carried out in the Materials Forming Laboratory of I.I.T., Madras, Chennai, India.
  • No Thumbnail Available
    Item
    Stress analysis of SUS 304 - Ceramics functionally graded beams using third order shear deformation theory
    (2008) Akhtar, K.; Kadoli, R.
    Kinematics for moderately thick rectangular beams satisfying zero shear strain on the top and bottom . surfaces is utilized to define the strain displacement relations involving the membrane, bending and higher order of displacements. Strain energy containing shear rotation term is deduced. The principle of stationary potential energy is used to obtain the static finite element equilibrium equations for the FGM (functionally graded material) beam with a uniformly distributed transverse load. FGM beams with continuous and smooth grading of metal and ceramics based on po wer law index are considered for the study. Equivalent single layer approach is followed for the evaluation of the constitutive matrix of the FGM beam. Numerical results are presented on the axialstresses and shear stresses in SUS304-Al3O3, SUS 304-ZrO2 and SUS 304-Si3N4FGM beams with clamped-clamped and simply supported boundary conditions. The effect of volume fraction of ceramic and metal on the nature of stress distribution through the thickness are investigated. The studies reveal that, the magnitude and distribution profile of static stresses in the beam depends on the power law index and also on the nature of load bearing surface, ie, whether the loading is on the ceramic rich face of the beam or metal rich face.
  • No Thumbnail Available
    Item
    Stress analysis of Antisymmetric angle ply sandwich plates- analytical evaluation of refined higher order shear deformation theories
    (CAFET INNOVA Technical Society 1-2-18/103, Mohini Mansion, Gagan Mahal Road, Domalguda, Hyderabad 500029, 2011) Swaminathan, K.; Sangwai, G.R.
    In this paper two refined higher order computational models with 9 DOF and 12 DOF are considered. Analytical formulation developed and solutions obtained for the first time using these models for the stress analysis of antisymmetric angle ply sandwich plate. In addition, higher order model proposed by Reddy and the first order model already reported in the literature are also considered for the evaluation. A simply supported plate with SS-2 boundary conditions is considered for the analysis. The equations of equilibrium are obtained using Principle of Minimum Potential Energy (PMPE). Solutions are obtained in closed form using Navier’s technique. In-plane stresses are computed using the three dimensional constitutive relationships and the transverse stresses by post processing technique. Extensive numerical results using all the models are compared with 3D elasticity solutions already available in the literature to decide the accuracy of model. After establishing accuracy of the solution method benchmark results and comparison of solutions are presented for multilayer sandwich plates. It is observed that ESL models with twelve DOF are accurate, efficient and simple. © 2011 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.
  • No Thumbnail Available
    Item
    Computational model for the transverse stress analysis of FGM plates - An assessment
    (2013) Swaminathan, K.; Naveenkumar, D.T.
    This paper presents the complete theoretical formulation and the analytical solutions for stress analysis of functionally graded material (FGM) plates using First-order Shear Deformation Theory (FSDT). The material properties are assumed to be isotropic along the plane of the plate and vary through the thickness according to the power law function. The governing equations of equilibrium are derived using Principle of Minimum Potential Energy (PMPE) and the analytical solutions are obtained in closed-form using Navier's solution technique. The effect of variation of side-to-thickness ratio, modulus of elasticity ratio, edge ratio and the power law function on the behaviour of the plate is studied. Numerical results are presented for the transverse displacement, the in-plane and the transverse stresses. © 2013 CAFET-INNOVA TECHNICAL SOCIETY.
  • No Thumbnail Available
    Item
    Strategy for refinement of nodal densities and integration cells in EFG technique
    (Techno-Press, 2016) Bhavana Patel, V.S.S.; Narayan, B.K.S.; Venkataramana, K.
    MeshFree methods have become popular owing to the ease with which high stress gradients can be identified and node density distribution can be reformulated to accomplish faster convergence. This paper presents a strategy for nodal density refinement with strain energy as basis in Element-Free Galerkin MeshFree technique. Two popular flat plate problems are considered for the demonstration of the proposed strategies. Issue of integration errors introduced during nodal density refinement have been addressed by suggesting integration cell refinement. High stress effects around two symmetrical semi-circular notches under in-plane axial load have been addressed in the first problem. The second considers crack propagation under mode I and mode II fracture loading by the way of introducing high stress intensity through line crack. The computational efficacy of the adaptive refinement strategies proposed has been highlighted. © 2016 Techno-Press, Ltd.
  • No Thumbnail Available
    Item
    Static deflection and thermal stress analysis of non-uniformly heated tapered composite laminate plates with ply drop-off
    (Elsevier Ltd, 2018) Ashok, S.; Jeyaraj, P.
    The effective design of tapered laminated composite structures subject to non-uniform temperature fields requires a thorough understanding of their static behaviour. In this study, a finite element analysis of tapered laminated composite plates with ply drop-off has been carried out to study the static deflection and normal stress patterns developed under non-uniform heating. The study revealed that the nature of the taper configuration, the nature of the applied temperature field and the structural boundary conditions influence the static deflection behaviour and the normal stresses developed in the tapered composite plates. It is found that the static deflection pattern of a tapered plate subject to a particular temperature profile is not sensitive to the nature of the taper configuration. It is also observed that the static deflection pattern of a tapered plate is significantly influenced by the nature of temperature field. Normal stress variation of tapered plates subject to various temperature fields reflects the nature of the temperature profile. Maximum normal stress occurs at locations where the highest temperature exists for that particular temperature field. The stresses are also influenced by the nature of the taper - Taper D plates experience low stresses while Taper B and Taper C plates experience similar values. It was also found that large variations in stresses are observed at resin pockets. © 2018
  • No Thumbnail Available
    Item
    Investigation on the eect of using rubber as core material in sandwich composite plate subjected to low-velocity normal and oblique impact loadings
    (Sharif University of Technology, 2019) Mahesh, V.; Joladarashi, S.; Kulkarni, S.M.
    In this article, the structural performance of composite plate under low-velocity impact is studied. Two forms of layup sequence, namely, Jute-Epoxy laminate (JE) and Jute-Epoxy-Rubber sandwich (JE-R-JE), were considered for evaluation. Special emphasis was on evaluating the inuence of normal and oblique loadings. Various dynamic parameters, such as energy, peak load, and deformation, were analysed in detail to study the eect of impact angle on both laminate and sandwich structures. Stress analysis of both laminate and sandwich structures was carried out to discuss the eect of introducing rubber as a core material. The results revealed that using rubber as a core material had a signicant eect on energy absorption. In addition, it was noticed that increasing the angle of impact would yield better performance of the composite plate. The results presented here may serve as benchmark for eective utilization of composite plates in low-velocity impact applications. © 2019 Sharif University of Technology. All rights reserved.
  • No Thumbnail Available
    Item
    Study on performance of infilled wall in RC framed structure using basalt fibre in cement mortar
    (Structural Engineering Research Centre, 2019) Jagadeesan, P.; Palanisamy, T.
    Normally, Reinforced Concrete (RC) framed structure is built by combination of structural and non-structural elements that may satisfy the design and architectural purpose. When RC framed structures are subjected to the static lateral loading, infilled wall and RC frame elements does not react together. At this time, infilled wall is subjected only compressive forces and does not support the tensile force. So, failure is happened due to lacking of ductility and poor interaction between frame elements and infilled wall. Therefore, the objective of this study is to improve the ductility and interaction between RC frame elements and infilled wall through suitable method of strengthening of infilled wall. In this research work, the two types of specimens such as infilled RC framed structure and infilled RC framed structure strengthened by reinforced cement mortar using basalt fibre were cast and tested under experimental and analytical investigation. One-fifth scale model of single-bay, two-storey plane RC framed structure were prepared and tested under cyclic loading with the help of 1000 kN capacity loading frame and foundation block. This study focuses the significant parameters such as load-deflection curve, ductility, energy dissipation capacity, initial stiffness and failure mechanism of infilled RC frame and infilled RC frame with basalt fibre in cement mortar. The result proves that basalt fibre reinforced cement mortar improves the strength, stiffness and ductility of infilled RC framed structure and make infilled wall as integral unit in RC framed structure. © 2019 Structural Engineering Research Centre. All rights reserved.