Abstract
In this paper, soil-structure interaction effects on the seismic response of multistory frame structure on raft
foundation are numerically analyzed. The foundation soil profile is assumed to consists of a clay layer of variable
thickness resting on bedrock. A modified plane-strain numerical model is formed in the software Plaxis, and both free
vibration analysis, and earthquake analysis for a selected ground motion accelerogram are performed. The behavior
of the structure is assumed to be linear elastic with Rayleigh viscous damping included. The behavior of the clay
layer is modeled with a Hardening soil model with small strain stiffness. The computed results in terms of
fundamental period and structural horizontal displacements for the case of fixed base and for different thicknesses of
clay layer are presented, compared, and discussed.
Key Words
earthquake; frame; fundamental period; horizontal displacements; response spectrum; seismic
load; soil-structure interaction
Address
Amina Botić: IPSA Institute, Put Života b.b, 71000 Sarajevo, Bosnia and Herzegovina
Emina Hadzalic, Anis Balić: University of Sarajevo - Faculty of Civil Engineering, Patriotske Lige 30, 71000 Sarajevo, Bosnia and Herzegovina
Abstract
During the manufacture of FGM plates, defects such as porosities can appear. Those can change the entire behavior of these plates. This paper aims to investigate the free vibration characteristics of porous functionally graded (FG) plates resting on elastic foundations. The Young's modulus of the plate is assumed to vary continuously through the thickness according to a power-law formulation, and the Poisson ratio is held constant. Different types of porosity distribution rates are considered. To examine the accuracy of the present formulation, several comparison studies are investigated. Effects of variation of porosity distribution rate, foundation parameter, power-law index and thickness ratio on the fundamental frequency of plates have been investigated.
Key Words
elastic foundation; free vibration analysis; functionally graded plate; imperfect plates; porosity distribution rate
Address
Aicha Kablia, Rabia Benferhat, Hassaine Daouadji Tahar: Department of Civil Engineering, University of Tiaret, Algeria; Laboratory of Geomatics and Sustainable Development, University of Tiaret, Algeria
Abstract
In this paper, we present the parameter identification for inelastic and multi-scale problems. First, the theoretical background of several fundamental methods used in the upscaling process is reviewed. Several key definitions including random field, Bayesian theorem, Polynomial chaos expansion (PCE), and Gauss-Markov-Kalman filter are briefly summarized. An illustrative example is given to assimilate fracture energy in a simple inelastic problem with linear hardening and softening phases. Second, the parameter identification using the Gauss-Markov-Kalman filter is employed for a multi-scale problem to identify bulk and shear moduli and other material properties in a macro-scale with the data from a micro-scale as quantities of interest (QoI). The problem can also be viewed as upscaling homogenization.
Key Words
Bayesian update; Gauss-Markov-Kalman filter; inelastic and multi-scale problems; parameter identification
Address
Cong-Uy Nguyen: Royallieu Center of Research, University of Technology of Compiègne/Sorbonne University Alliance, France; Institute of Scientific Computing, Technical University of Braunschweig, Germany
Truong-Vinh Hoang: Chair of Mathematics for Uncertainty Quantification, RWTH Aachen University, Germany
Emina Hadzalic: Faculty of Civil Engineering, University of Sarajevo, Bosnia and Herzegovina
Simona Dobrilla: Royallieu Center of Research, University of Technology of Compiègne/Sorbonne University Alliance, France; Institute of Scientific Computing, Technical University of Braunschweig, Germany
Hermann G. Matthies: Institute of Scientific Computing, Technical University of Braunschweig, Germany
Adnan Ibrahimbegovic: Royallieu Center of Research, University of Technology of Compiègne/Sorbonne University Alliance, France; Institut Universitaire de France, France
Abstract
Over-coating is one of the most popular engineering practices to strengthen Reinforced Concrete (RC) structures, due to the relative quickness and ease of construction. It consists of an external coat bonded to the outer surface of the structural RC element, either by the use of chemical adhesives, mechanical anchor bolts or simply mortar injection. In contrast to these constructive advantages, the numerical estimation of the bearing capacity of the strengthened reinforced concrete element is still complicated, not only for the complexity of modelling a flexible membrane or plate attached to a quasi-rigid solid, but also for the difficulties that raise of simulating any potential delamination between both materials. For these reasons, the standard engineering calculations used in the practice remain very approximated and clumsy. In this work, we propose the formulation of a new 2D solid-layer finite element capable to link a solid body with a flexible thin layer, as it were the "skin" of the body, allowing the potential delamination between both materials. In numerical terms, this "skin" element is intended to work as a transitional region between a solid body (modelled with a classical formulation of a standard quadrilateral four-nodes element) and a flexible coat layer (modelled with cubic beam element), dealing with the incompatibility of Degrees-Of-
Freedom between them (two DOF for the solid and three DOF for the beam). The aim of the solid-layer element is to simplify the mesh construction of the strengthened RC element being aware of two aspects: a) to prevent the inappropriate use of very small solid elements to simulate the coat; b) to improve the numerical estimation of the real bearing capacity of the strengthened element when the coat is attached or detached from the solid body.
Key Words
delamination; finite element formulation; solid-layer bonding
Address
Arturo Suárez-Suárez: Postgraduate Studies and Research Section, ESIME-UZ, Instituto Politécnico Nacional, Mexico
Norberto Domínguez-Ramírez: Postgraduate Studies and Research Section, ESIA-UZ, Instituto Politécnico Nacional, Mexico
Orlando Susarrey-Huerta: Postgraduate Studies and Research Section, ESIME-UZ, Instituto Politécnico Nacional, Mexico
Abstract
In the present work, a new photothermoelastic model based on Moore-Gibson-Thompson theory has been constructed. The governing equations for orthotropic photothermoelastic plate are simplified for two-dimension model. Laplace and Fourier transforms are employed after converting the system of equations into dimensionless form. The problem is examined due to various specified sources. Moving normal force, ramp type thermal source and carrier density periodic loading are taken to explore the application of the assumed model. Various field quantities like displacements, stresses, temperature distribution and carrier density distribution are obtained in the transformed domain. The problem is validated by numerical computation for a given material and numerical obtained results are depicted in form of graphs to show the impact of various theories of thermoelasticity along with impact of moving velocity, ramp type and periodic loading parameters. Some special cases are also explored. The results obtained in this paper can be used to design various semiconductor elements during the coupled thermal,
plasma and elastic wave and other fields in the material science, physical engineering.
Key Words
carrier density loading; Fourier transform; Laplace transform; Moore-Gibson-Thompson
thermoelastic model; moving normal force; photothermoelastic orthotropic; ramp type thermal source
Address
Rajneesh Kumar: Department of Mathematics, Kurukshetra University, Kurukshetra, Haryana, India
Nidhi Sharma: Department of Mathematics, Maharishi Markandeshwar University, Mullana, Ambala, Haryana, India
Supriya Chopra: Department of Mathematics, Government College for Women, Ambala city, Haryana, India
