Jamal Zamani

Jamal Zamani
Khaje Nasir Toosi University of Technology | KNTU · Faculty of Mechanical Engineering

PhD

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49
Publications
10,105
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Skills and Expertise

Publications

Publications (49)
Article
Full-text available
Explosive welding was used to produce scarf joint between aluminum and copper plates. This process is known as explosive scarf welding (ESW). In a scarf joint, the final bond interface is oblique. In this study, chamfered end of aluminum and copper plates were joined explosively and named scarf joint, employing changes in chamfered angle at differe...
Article
Dynamic response analysis of structures subjected to underwater explosion (UndEx) loading has been always an interesting field of study for ship designers and metal forming specialists. Understanding the deformation and rupture mechanism of simple structures plays an important role in successful designing of a reliable structure under this kind of...
Article
Full-text available
The objective of this research is determining the buckling load of composite truncated conical shells under external loading by theoretical and numerical methods. The boundary conditions are assumed to be clamped. At first, basic equations and stability relations of conical shells were derived. The analysis is carried out using Donnel-type stabilit...
Article
Due to different influential parameters that affect an explosive forming process, this classic method of metal forming can potentially be considered as one the most complicated practical approaches to forming metallic shells and plates. Focusing on the importance of the energetic efficiency during an explosive forming procedure, the explosion pheno...
Article
Full-text available
Explosive loading of closed cylindrical structures is one of the most complicated types of high rate loadings that can be applied on fully closed structure. Considering the complexities and unknown factors that affect the dynamic-plastic behaviour of a fully closed tubular shell under internal blast loading, the main objective of this article is to...
Article
A Shock tube is a piece of equipment in which, by creating a pressure difference between the driver and the driven section via the bursting membrane, it has the ability to generate shock waves with very short rise time. One of the important parameters in the shock tube is the planar shock wave and the distance of its formation along the driven sect...
Article
This paper suggests a new optical system for measuring shock wave characteristic that is installed in a shock tube. This shock tube has an innovative pneumatic rapid opening valve designed to open from the center of the tube to the corners. In this measurement system, a plate has placed in front of the shock wave. The plate displacement has measure...
Article
The numerical shock velocity–particle velocity data were obtained by the use of the conservative laws and data were fitted to the linear and quadratic relation with respect to the particle velocity in various temperatures. An equation was derived for the second parameter of the general Hugoniot relation that could be obtained at every initial tempe...
Conference Paper
Full-text available
One of the main goals of researchers in the laser melting processes of metal powders is optimization of required parameters in order to reach the properties of manufactured parts to the casting, or wrought material properties. Selective Laser Melting (SLM) in comparison with conventional manufacturing methods allows the production of three - dimens...
Article
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A time delay is created between elastic and plastic wave fronts because of the difference between the elastic longitudinal sound speed and the plastic shock wave velocity. Over a short propagation distance, the time delay between the elastic and plastic wave fronts at the Hugoniot elastic limit (HEL) is nonlinear, while at larger distances, the tim...
Article
In this article, the stress–time or speed–time relations for steady weak shock wave fronts and their effective parameters were studied for solid metals (except alkaline metals). The purpose was to determine the effective parameters for steady shock wave fronts and find the relations for prediction of the shape of these profiles in pure metals. Firs...
Article
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One of the main goals of researchers in the laser sintering process of metal powders is the optimization of process parameters in order to reach the properties of manufactured parts to the raw material properties. For this purpose, many experiments have been performed and parameters such as density, microhardness, macro hardness, strength, surface...
Article
Full-text available
One of the main goals of researchers in the laser sintering process of metal powders, is optimization of process parameters in order to reach the properties of manufactured parts to the raw material properties. For this purpose, many experiments have been performed and parameters such as density, hardness, strength and surface quality in different...
Article
Full-text available
Powder bed fusion is an additive manufacturing method which allows production of complex parts, in a shorter time compared to the conventional fabrication methods. During the last 60 years, Fe–Cu powders were widely used because of their anti-friction behavior and superior mechanical properties. Therefore, Fe–Cu powder has been selected as the basi...
Article
Full-text available
Powder bed fusion is an additive manufacturing method which allows production of complex parts, in a shorter time compared to the conventional fabrication methods. During the last 60 years, Fe–Cu powders were widely used because of their anti-friction behavior and superior mechanical properties. Therefore, Fe–Cu powder has been selected as the basi...
Article
Full-text available
Direct metal laser sintering is an additive manufacturing method which allows manufacturing of complex parts without using dies in short time. In the present study, direct metal laser sintering of steel 316 powder has been studied. Response surface methodology has been used for the design and analysis of experiments. Nd:YAG laser with a maximum pow...
Article
Full-text available
In this investigation, composite metal foams were produced by casting aluminum around hollow ceramic spheres arranged in steel mesh structures. This study proposes that “cell arrangement” should be considered as an important parameter in controlling the mechanical properties of CMFs, which can be applied in energy absorber designs. Metal foams with...
Article
Full-text available
Today, to reduce the cost and increase the safety, test devices like conic shock tube have been widely used to investigate the underwater explosion phenomenon and its impact on structures. A shock tube is designed, manufactured and utilized in the mechanic of explosion laboratory of mechanic faculty of K.N. Toosi University of Technology to study t...
Article
Full-text available
This paper presents an experimental study on interaction effects of apparent density and heat transfer charactristics of metal powder by Direct Metal Laser Sintering device which is developed at K. N. Toosi university of technology. Selective Laser Melting (SLM) is a direct fabrication of part through layer by layer powder deposition and successive...
Article
Full-text available
One of the main goals of researchers in metal powders laser sintering, is optimization of process parameters in order to close out the main properties of the raw materials have been produced to the piece. For this purpose, many experiments have been carried and parameters such as density, hardness, micro hardness, strength, surface finish, appearan...
Article
One of the methods to investigate the phenomenon of explosion underwater and its impact on the structures is to use the conical shock tube. These tubes produce a lot of pressure using a tiny explosive charge. In this essay, the geometry of the established/manufactured explosive shock tube is demonstrated first and the results of the experiments ope...
Article
Full-text available
An adiabatic constitutive model is proposed for large strain deformation of polycarbonate (PC) at high strain rates. When the strain rate is sufficiently high such that the heat generated does not have time to transfer to the surroundings, temperature of material rises. The high strain rate deformation behavior of polymers is significantly affected...
Article
This paper presents an analysis of the dynamic behavior of thick-walled cylinder using Levy-Mises flow rule in the assumption of a non-linear strain rate hardening behavior under high strain rate loading. The theoretical model to be developed in this work applies indirect use of dynamic strength of material characterized by a non-linear relation an...
Article
Full-text available
This paper develops a new physically based model to investigate face centered cubic (FCC) metals and alloys under high strain rate loadings (\gt104 s−1) which includes kinematics and constitutive equations for the propagation of elastic and steady plastic waves. The model’s formulations are based on the rate of the conservation energy law that incl...
Article
Full-text available
This paper presents analysis of the dynamic behavior of thick-walled cylinder in the assumption of non-linear strain rate hardening behavior under high strain rate loading before any fracture on the surface. The theoretical model applies both to direct and indirect use of dynamic strength of material and instant boundary condition to establish diff...
Article
Full-text available
Finite element simulations of pressure-shear plate impact experiment are conducted to investigate the plastic behaviour of OFHC copper under high strain rate loadings. OFHC copper is sandwiched between two harder plates which possess enough strength to remain elastic under high velocity impact. Two methods are implemented to achieve shear flow stre...
Article
Given the numerous applications of thick-walled cylinders, it is important to know the behavior of these structures. There are so many relationships for cylinders and spheres under dynamic loading which have been found mainly based on other experimental models. Hence derive an analytical model of the behavior of structures under internal and high-r...
Article
This paper presented a theoretical model to investigate steady plastic shock wave on FCC metals. The method included shear flow stress according to effective parameters and based on microstructure and dynamics of dislocation method. The aim of this paper was to achieve final relation between shear stress and plastic stretch with presenting constitu...
Article
Full-text available
An elastic solution of cylinder-truncated cone shell intersection under internal pressure is presented. The edge solution theory that has been used in this study takes bending moments and shearing forces into account in the thin-walled shell of revolution element. The general solution of the cone equations is based on power series method. The effec...
Article
Full-text available
The primary objective of this research is to determine the accuracy of a typical turbine blade wax pattern that includes common areas (such as root, platform and airfoil) in all turbine blades, which are produced by soft tooling room temperature vulcanization (RTV) mold methods, epoxy molds and silicone rubber molds and also to compare them. It is...
Article
Full-text available
In most blast loading structure analyses, it is assumed that the load acts uniformly on a target area. For the rationable design, it is useful to have a quantitative criterion to determine at which maximum distance the standoff can be placed to assume a uniform pressure distribution. Surprisingly, no standard criterion was found in the literature a...
Article
Full-text available
In this work, the impact behavior of sandwich beams with asymmetrical and symmetrical Functionally Graded (FG) cores are investigated using finite element method. The ballistic limit and residual velocity of several sandwich beams with a FG core are studied. The ratios of residual kinetic energy as well as perforation energy to initial kinetic ener...
Article
Full-text available
In this article, stability of composite conical shells subjected to dynamic external pressure is investigated by numerical and experimental methods. In experimental tests, cross-ply glass woven fabrics were selected for manufacturing of specimens. Hand-layup method was employed for fabricating the glass-epoxy composite shells. A test-setup that inc...
Article
Full-text available
This paper presents a novel set-up designed to investigate plastic deformation of a metal at high strain rates. The set-up is similar to conventional split Hopkinson pressure bar but the striker bar is eliminated and instead of it a spherical projectile, accelerated to high velocity with a two-stage light-gas gun, impacts and penetrates in a steel...
Article
A constitutive model is presented for large strain deformation of polycarbonate (PC) at high strain rates (above 102 s−1). The proposed model considers the primary process (α) and the two secondary rate-activated processes (β and γ). It is shown that the secondary transitions in the material affect the yield and post yield behavior of the material...
Article
The analysis of the behavior of thin walled shells has always been a challenging case of study. The focus of this research is on the experimental analysis of such shells under internal pressure loading with different strain rates. A hydrostatic loading machine has been designed and manufactured to achieve such an objective and then a complete set o...
Article
The special and unique advantages of explosive forming, has developed its use in different industries. Considering the important influence of improving the current explosive forming techniques on increasing the efficiency and control over the explosive forming procedure, the effects of air and water as the energy-conveying medium, and also their di...
Article
Full-text available
This article presents the results of experimental and analytical studies on the response of steel and aluminium square plates with different thicknesses subjected to blast loading. Based on the blast wave details and the scaling law for explosions, a method of determining the blast load is proposed in which ballistic pendulums do not need to be uti...
Article
Full-text available
The dynamic plastic response of structures under blast loading and underwater explosion has found important applications in the design of energy-absorbing and collision protection devices. This paper presents the results of analytical and experimental studies on the response of steel and aluminium circular plates in two different media of air and w...
Article
The analysis of the behavior of thin walled shells has always been a challenging case of study. The focus of this research is on the experimental analysis of such shells under internal pressure loading with different strain rates. A hydrostatic loading machine has been designed and manufactured to achieve such an objective and then a complete set o...
Article
The special and unique advantages of explosive forming, has developed its use in different industries. Considering the important influence of improving the current explosive forming techniques on increasing the efficiency and control over the explosive forming procedure, the effects of air and water as the energy-conveying medium, and also their di...
Conference Paper
Full-text available
This paper explores the concepts of energy transfer architecture in one of rapid prototyping (RP) process. Named Stereolithography (SLA). The functional requirements of a rapid prototyping system are speed and accuracy, and they are both functions of vendor defaulted and user selected manufacturing parameters. Accuracy is evaluated by dimensional....
Article
In most of the engineering structures, specially moving ones and generally in structures under dynamic and static loadings, energy absorber systems are implemented for preventing or reducing damages. These systems are employed in all on-road vehicles, train wagons, airplanes and ships. Energy absorbers are subjected to two forms of in-plane and out...
Article
The paper discusses all different types of folding mechanism in honycomb structures. A new folding mechanism named "Mixed Mechanism" is introduced for determining the crushing strength of hexagonal cell honeycombs subjected to axial quasi-static loading. The theoretical solution has been compared with experimental results published in literatures a...
Article
Full-text available
Constitutive equations are being considered for metallic crystals under very high strain rates loadings. An analytical solution of the steady state propagation of plastic shocks is proposed. Constitutive relations are provided for the kinematics and kinetics of metals with micron-scale grains. The effect of strain, strain rate are being considered....

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