Loading...
Search for:
pressure-loading
0.005 seconds
A study on the axial stresses of P-FGM, SFGM and E-FGM plates under pressure loading using the energy concept
, Article 27th Congress of the International Council of the Aeronautical Sciences 2010, ICAS 2010, 19 September 2010 through 24 September 2010, Nice ; Volume 3 , 2010 , Pages 2060-2068 ; 9781617820496 (ISBN) ; Abedian, A ; Sharif University of Technology
2010
Abstract
In this study the energy concept along with the classical plate theory (CPT), first and third order shear deformation theories (FSDT and TSDT) are used to predict the large deflection and through the thickness stresses of a FGM plate. For defining the volume fraction of the FGM constituent materials three different functions are considered; simple power-law (PFGM), exponential (E-FGM) and sigmoid (S_FGM) functions. Power-law and exponential functions are commonly used tocontrol the variations of properties of FGMs. However, with both functions, a stress concentration appears due to abruptchange of the volume fraction of the constituents. Therefore, a sigmoid FGM is used to define a new...
Elasto-Plastic Design of Thick-Walled FG Vessels under Pressure or Temperature Gradient Loadings
, M.Sc. Thesis Sharif University of Technology ; Kargarnovin, Mohammad Hossein (Supervisor)
Abstract
Nowadays functionally graded materials have many applications in various industries. One of these applications can be the manufacturing of thick-walled vessels. Thick-walled vessels under internal pressure and high temperatures gradient require materials with higher strength, like Functionally Graded Materials (FGM) and can be reinforced by some mechanical processes like autofrettage. In this process under certain loading some part of vessels enters into plastic zone and upon unloading some residual stresses will be generated. Moreover it is very important to find out the depth of this plastic zone, In addition, minimizing the stress distribution vs. depth of plastic zone under applied...
Durability Evaluation and Health Monitoring of Microcracked Slag-Based Geopolymer Concrete Due to Step by Step Pressure Loading
, M.Sc. Thesis Sharif University of Technology ; Ghaemian, Mohsen (Supervisor) ; Toufigh, Vahab (Co-Supervisor)
Abstract
The goal of this research is to study the effect of local microcracking due to step by step pressure loading on the durability properties of geopolymer concrete. To better understand the behavior of GGBS-based GPC under different pressure stress levels, some experiments such as water permeability and water absorption conducted on the samples at each state of damage. Also, non-destructive tests such as ultrasonic waveform and pulse velocity (UPV) was used to quantify the extent of damage at each step. GGBFS and a blend of sodium silicate solution and 10 molar sodium hydroxide solution with SSSH⁄ ratio of 2 were used for production of GPC samples. GPC, OGPC and OPC samples with water to binder...
Analysis of Al A359/SiCp functionally graded cylinder subjected to internal pressure and temperature gradient with elastic-plastic deformation
, Article Journal of Thermal Stresses ; Volume 34, Issue 10 , May , 2011 , Pages 1054-1070 ; 01495739 (ISSN) ; Naghdabadi, R ; Arghavani, J ; Sharif University of Technology
2011
Abstract
In this article, an analytical elastic-plastic solution for thick-walled cylinders made of Functionally Graded Materials (FGMs) subjected to internal pressure and thermal loading is presented. Based on the experimental results, a mathematical model to predict the yielding through the thickness of FG AlA359/SiCp cylinder is developed. It is shown that under the temperature gradient loading, there is a point in the cylinder where the circumferential stress changes from compressive to tensile. The position of this point depends on the geometry and material properties of the FG cylinder and is independent of the temperature gradient
A combined passive and active musculoskeletal model study to estimate L4-L5 load sharing
, Article Journal of Biomechanics ; 2017 ; 00219290 (ISSN) ; Arjmand, N ; Shirazi Adl, A ; Rahimi Moghaddam, T ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
A number of geometrically-detailed passive finite element (FE) models of the lumbar spine have been developed and validated under in vitro loading conditions. These models are devoid of muscles and thus cannot be directly used to simulate in vivo loading conditions acting on the lumbar joint structures or spinal implants. Gravity loads and muscle forces estimated by a trunk musculoskeletal (MS) model under twelve static activities were applied to a passive FE model of the L4-L5 segment to estimate load sharing among the joint structures (disc, ligaments, and facets) under simulated in vivo loading conditions. An equivalent follower (FL), that generates IDP equal to that generated by muscle...
A combined passive and active musculoskeletal model study to estimate L4-L5 load sharing
, Article Journal of Biomechanics ; Volume 70 , March , 2018 , Pages 157-165 ; 00219290 (ISSN) ; Arjmand, N ; Shirazi Adl, A ; Rahimi Moghaddam, T ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
A number of geometrically-detailed passive finite element (FE) models of the lumbar spine have been developed and validated under in vitro loading conditions. These models are devoid of muscles and thus cannot be directly used to simulate in vivo loading conditions acting on the lumbar joint structures or spinal implants. Gravity loads and muscle forces estimated by a trunk musculoskeletal (MS) model under twelve static activities were applied to a passive FE model of the L4-L5 segment to estimate load sharing among the joint structures (disc, ligaments, and facets) under simulated in vivo loading conditions. An equivalent follower (FL), that generates IDP equal to that generated by muscle...
Constitutive Modeling of Brittle Materials (Polymer Concrete and Rock) under Triaxial Compression Loading
, M.Sc. Thesis Sharif University of Technology ; Toufigh, Vahab (Supervisor)
Abstract
Understanding mechanical behavior of engineering materials plays an important role in prediction of material response and helps to analysis and design of engineering structures. In this thesis, behavior of polymer concrete (PC) with three different epoxy resin ratios, ordinary cement concrete (OCC), lightweight concrete (LWC), lime mortar soil (LMS), four various types of sandstone and granite was investigated under uniaxial and triaxial compression. In order to predict the mechanical behavior of aforementioned brittle materials, their behavior was simulated in terms of axial stress and volumetric strain versus axial strain. For computation of volumetric deformation and softening behavior,...
Fabrication of porous NiTi alloy via powder metallurgy and its mechanical characterization by shear punch method
, Article Russian Journal of Non-Ferrous Metals ; Volume 53, Issue 2 , April , 2012 , Pages 169-175 ; 10678212 (ISSN) ; Hasannaeimi, V ; Saebnoori, E ; Shahrabi, T ; Sadrnezhaad, S. K ; Sharif University of Technology
Abstract
In this study, Porous NiTi shape memory alloy has been produced by mechanical alloying of the elemental Ni and Ti powders. The compacting process was done at two temperatures (warm and cold press) and then sintering at 980 and 1050°C was performed on the specimens. Microstructure and mechanical prop-erties of the samples were investigated by optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction. Moreover, shear punch test (SPT) employed to investigate the effect of compaction pressure and sintering temperature on the mechanical properties of the fabricated samples. It was revealed that warm compaction/sintering resulted in 15% yield stress improvement and 20% ultimate...
Nonlinear analysis of FGM plates under pressure loads using the higher-order shear deformation theories
, Article Composite Structures ; Volume 89, Issue 3 , 2009 , Pages 333-344 ; 02638223 (ISSN) ; DehghanManshadi, B ; Abedian, A ; Sharif University of Technology
2009
Abstract
In this study, the energy concept along with the first- and third-order shear deformation theories (FSDT and TSDT) are used to predict the large deflection and through the thickness stress of FGM plates. These responses are studied and discussed as a function of plate thickness and the order "n" of a power law function which is considered for the through the thickness variation of the properties of the FGM plate. The results show that the energy method powered by the FSDT and FSDT is capable of predicting the effects of plate thickness on the deformation and the through the thickness stress. Here, also the effects of power "n" on the plate response is clearly depicted. Notably, the...