Tohid Mirzababaie Mostofi

University of Eyvanekey | EYC · Department of Mechanical, Computer and Electronic Engineering

A series of twenty experimental tests were first carried out to assess the large transverse deformation of double-layered rectangular plates subjected to gas mixture detonation load. Specimens were made from a combination of an aluminum alloy front layer (the impulse-receiving face) and a mild steel back layer. Four different types of thickness con...

The present study deals with the numerical simulation of the dynamic response of the pure aluminum AA1050 tube under internal gas mixture detonation loading. This practical topic involves structural large plastic deformation, fluid motion, and chemical reaction, and detonation wave/structure interaction. Therefore, the Fluid-Structure Interaction (...

In this article, an immersed boundary method which couples a Lagrangian structure solver with an Eulerian fluid solver with a chemistry model capable of detonation computation for H2-O2 is developed to achieve the fluid-structure interaction, the deformation, and the damage of a thin plate subjected to a gaseous detonation loading. The Johnson-Cook...

Barriers are introduced as an efficient method for the protection of infrastructures and people from overpressure effects owing to accidental gaseous explosions. Therefore, capturing the pressure wave propagation in front of and behind the barrier plays an important role in designing a protective wall and hazard analysis of pipeline explosion accid...

The present study describes the center of mass deformation of mild steel triangular plate under C2H2–O2 gaseous detonation loading through non-dimensional analysis. The non-dimensional analysis is conducted to suggest a new non-dimensional number for predicting the dynamic response of the clamped plate under confined impulsive loading. Experimental...

The rock-cutting phenomenon can be considered a challenging problem from a numerical modeling point of view due to the complexity of the physics that comes from the interaction between the rock and the cutter. The present research was aimed at the presentation of a numerical simulation of the rock-cutting process based on the finite element method...

The study of shock wave propagation in a detonation chamber is of great importance as a part of the plate forming process. Investigations related to the effects of premixed gas detonation on the deflection of a plate require in-depth examination. An Eulerian-Lagrangian numerical simulation is conducted using the space-time conservation element and...

The present research paper deals with a combined experimental and numerical assessment of the deformation mode and failure mechanism of welded rectangular plates exposed to three successive uniform blast loading. To perform the experimental study, three different categories of 0 W (a plate without any weld seam), 1 W (a plate with a single weld sea...

The main focus of the present research study is on developing a profound understanding of the free explosive forming of metallic plates using repeated underwater shock-wave loading. To this end, experimental and numerical investigations of plastic deformation of 3 mm thick Armco® Iron plates were performed. Two series of experiments were conducted...

During a high-velocity plate forming process accompanied by dynamic loading, a large deformation is generated in a very short time. Gaseous detonation in an obstructed channel is a good way of producing interior shock waves. Pressure waves with high strength have interacted with a plate as a fundamental mechanism of the whole forming process. This...

The present paper aims to use the concurrent coupling approach of Finite Element Method (FEM) and Discrete Element Method (DEM) to simulate the surface cracking and the local damage in ceramic coating-substrate structures due to mechanical and thermomechanical loading. DEM is an efficient approach for studying the brittle fracture phenomenon at the...

An elaborate numerical study with a validated LS-DYNA® immersed boundary method fluid-solid interaction code is used to characterize the influence of pre-detonation pressure, ignition point location and time duration on plastic deformation of thin steel plates subjected to hydrogen-oxygen gaseous detonation. Simulation relies on the modeling of det...

In this paper, the metal foams of AA332 and AA1067 alloys were produced using an economical technique called the pressurized infiltration process. The main advantage of this technique is controlling the space holder particle size during the production process which has a considerable effect on the mechanical properties of the foam and higher energy...

Sandwich panels that can be used as an explosion shield are important structures for absorbing explosion energy. Crushing and plastic deformation of the core with the plastic bending of the faces are the main factors in absorbing the explosion energy in this sandwich panel. Structural components undergo permanent deformation after explosion and ene...

Dynamic compaction of Aluminum powder using gas detonation forming technique was investigated. The experiments were carried out on four different conditions of total pre-detonation pressure. The effects of the initial powder mass and grain particle size on the green density and strength of compacted specimens were investigated. The relationships be...

In this paper, the gas mixture detonation technique was utilized for impact spot welding of dissimilar metallic plates. The gas detonation produces shock waves to accelerate a high-strength projectile towards a long smooth barrel. After the collision, the flyer plate accelerates towards the base plate and spot joining is obtained. In this series of...

In the current study, an experimental investigation and modelling of the large plastic deformation of single-layered and multi-layered metallic targets made of either aluminum alloy or mild steel or a combination of these materials impacted by a rigid spherical projectile were presented. To conduct experiments, eight different layering configuratio...

In this paper, the effect of differed loading conditions, as well as structure geometries on the behavior of sandwich panel structures under uniform blast loading, has been investigated. For this, a full 3D numerical model by using ABAQUS/Explicit commercial software was employed in order to simulate the dynamic response and plastic deformation of...

In the current research, the plastic behavior of circular plates under successive intense dynamic loading was investigated. In the experimental section, a ballistic pendulum apparatus was used to apply dynamic loads and aluminum alloy plates with single- and multi-layered compositions. To simultaneously investigate the deformation profile as well a...

In the current research study, the large plastic deformation and failure mechanism of sandwich structures with aluminum face sheets and pumice core under low-velocity impact loading have been investigated. The drop hammer testing machine was used to apply the impact load on the specimen at seven different energy levels 34.3, 68.6, 102.9, 137.2, 171...

In this paper, the impact spot welding of metallic plates was investigated both experimentally and numerically using a single-stage gas mixture detonation apparatus. The impact spot welding process was carried out on aluminum alloy and steel materials using rigid steel projectiles. In this process, the mixture of oxygen and acetylene was detonated...

A series of 112 experiments were conducted to investigate the response of monolithic and multi-layered metallic plates under repeated uniform impulsive loading up to five times. 15 various testing groups were considered to study the effects of different charge masses, layering configurations, layering arrangements, layer thicknesses, and stand-off...

The effect of polyurea coating on the structural response of metallic plates is still a challenge for the industry and scientific community. In this paper, experimental and numerical investigations were carried out to study the influence of polyurea coating as a strengthening layer on the dynamic plastic response and resistance of aluminum plates u...

One of the main objectives of impact mechanics is the design of a structure resistant to explosion by introducing a structure with a special design pattern while maintaining its lightweight conditions. In this study, the plastic deformation and failure pattern of quadrangular metallic plates under localized impulsive loading were investigated due t...

One of the main aims of the current study is the experimental investigation and optimization of the dynamic response of polymer-coated aluminum plates under impulsive load. In the experimental study, the effect of several important parameters on the free forming of these structures under gas mixture detonation load, including the effect of aluminum...

Manufacturing products using powder compaction is one of the most widely used methods in the industry. In this paper, dynamic compaction of aluminum powder under low-velocity impact loading was investigated using a drop hammer testing machine along with the optimization of effective parameters in this process. In this series of experiments, the gre...

In this paper, an experimental and numerical study on the inelastic deformation of fully clamped circular, rectangular, and triangular plates under the low-velocity hydrodynamic loads has been conducted using the drop-hammer machine. In the experimental section, steel and aluminum plates with three different geometries of circular, rectangular, and...

In the present study, the experimental study and regression analysis of the dynamic response of circular plates under uniform and localized blast loading were investigated. To this end, several experiments were performed on steel plates under different conditions in the experimental section. In order to complete the database and perform a comprehen...

In this paper, a non-dimensional analysis approach has been used to propose two empirical equations based on dimensionless numbers to predict the maximum transverse permanent deflection-thickness ratio of single-layered quadrangular plates under uniformly and locally distributed dynamic loading. In the presented dimensionless numbers, the effect of...

In the present study, the experimental investigation and regression analysis of the large plastic deformation of square and rectangular plates subjected to extreme dynamic loading with uniform and localized distribution were discussed. In the experimental section, 5 experiments were conducted on mild steel plates with different thicknesses. To perf...

In the current study, an experimental study and modelling of the penetration behavior of single-layered and multi-layered targets made of either aluminum alloy or mild steel or a combination of these materials impacted by a spherical projectile were introduced. For conducting 66 experiments, eight different layering configurations consist of monoli...

This paper dealing with an experimental study, numerical simulation, and mathematical modelling of the dynamic response of single-layered and double-layered circular plates under localized impulsive loading. In the experimental section, six experiments were conducted on double-layered configurations made of copper-aluminum plates (2mm+2mm) under di...

In the present study, the deformation pattern in impact spot-welded plates with flat and spherical-nosed projectiles using gas mixture detonation set up has been investigated and compared with numerical simulations. The steel plate with a thickness of 4mm was considered as a base plate and steel plates with 1, 2, and 3mm thicknesses were selected a...

Spot welding process due to its ability to create a qualitative connection between metal plates and the absence of restrictions on old welding methods such as the impossibility of welding metals by many differences in their melting point is considered as one of the fastest and most economical methods. In this method, an atomic bonding is created on...

In the last decade, the gas mixture detonation forming (GDF) method has been introduced as a novel and alternative method instead of other high-velocity forming (HVF) methods such as the explosive method. Due to the lack of research in this field, the present study investigates the free and die forming of circular metallic plates under gas mixture...

In this paper, the large inelastic deformation and failure mechanism of single and multi-layered circular plates under repeated uniform impulsive loading were studied. The ballistic pendulum was used to conduct a series of experiments on aluminum alloy plates with different structural configurations. Three different layering configurations includin...

In impact mechanics, layered targets are important due to their high resistance to projectiles penetration. This paper deals with the analytical and numerical analysis of the penetration of tantalum projectiles on semi-infinite ceramic-metal layered targets. In the analytical study, a new modified analytical model based on the analytical model of F...

In this paper, a large-scale experimental study has been conducted in order to evaluate the high-velocity compaction of aluminum powder using the Gas Detonation Forming (GDF) processing technique. In this series of experiments, the effect of the distribution of grain particle size, initial powder mass, and loading conditions on green density and st...

In this paper, a non-dimensional analysis approach has been used to propose three empirical equations based on dimensionless numbers to predict the maximum transverse permanent deflection-thickness ratio of single-layered circular plates under uniformly and locally distributed dynamic loading. The effect of plate geometry, the impulse of applied lo...

A single-stage gas detonation apparatus was used for the free forming of metallic-polymeric structures. In the experimental section, to improve the performance of aluminum plates under gas mixture detonation loading, a layer of polyurea material was sprayed onto the back surface of the metallic plate. In order to investigate the effect of the thick...

In this study, numerical investigation and non-dimensional modeling of the dynamic response of steel and aluminum alloy plates reinforced with polymeric layers impacted by rigid projectiles with different geometries were investigated. In the numerical modeling section, the ABAQUS finite element software and PolyUMod were used to simulate the proces...

Due to the ability of the spot-welding process to create a quality connection between metal plates, especially those with very different mechanical properties, this process has been taken into consideration in recent years. In this method, when two metallic plates welded together under high applied pressure, an atomic bonding is created at the surf...

The objective of this paper is an experimental investigation and numerical modelling of large plastic deformation of metallic-polymeric bilayer plates under gas mixture detonation load. For this, the gas detonation forming apparatus was used in the experimental section to perform 40 experiments under various experimental conditions. The experimenta...

In this paper, the effect of coupled bending and membrane strains on the large plastic deformation of rectangular plates due to impact loading is investigated both analytically and experimentally. The energy approach based on upper bound solution has been used in order to predict the maximum permanent deflection of rectangular plates. By assuming a...

In this research, a series of experiments were first performed to evaluate the plastic deformation of rectangular aluminum plates reinforced by polymeric coating under gas mixture detonation loading. Four different types of thickness configurations were chosen to investigate the effect of front and back layer thicknesses on the deformation resistan...

In this paper, the effect of coupled bending and membrane strains on the large plastic deformation of rectangular plates due to impact loading is investigated both analytically and experimentally. The energy approach based on the upper bound solution has been used in order to predict the maximum permanent deflection of rectangular plates. By assumi...

In this study, a novel processing technique, namely gas mixture detonation method, was used for large plastic deformation of thin rectangular aluminum plates reinforced by polymeric coating. Based on this new idea, a series of experimental tests were conducted on plastic behavior of metal-elastomer bilayer structures with the aim of increasing the...

In this paper, the dynamic plastic response of double-layered circular metallic plates subjected to localized impulsive loading was investigated both numerically and empirically. A numerical model was developed in commercial finite element code ABAQUS/Explicit via a user user-defined FORTRAN subroutine in conjunction with the Johnson–Cook thermo-vi...

Explosive compaction process of metallic powders has been studied using a semi-empirical method. This method utilizes dimensional analysis along with genetic programming approach to obtain an expression relating the final density of compacts to the effective parameters during compaction process such as shock compaction energy, properties of metalli...

The parametric study results for double-layered plates 3+3 mm, 4+2 mm, and 2+4 mm have been summarized in Table A, B, and C, respectively.

The problem of studying plastic response of structures loaded dynamically has been extensively investigated over many years. A survey of literature on dynamic plastic behaviour of plates subjected to impulsive loading reveals that most analytical studies on fully clamped thin quadrangular plates consider bending moments and membrane forces separate...

This paper presents experimental and analytical investigation of the dynamic inelastic response of rectangular metal plates subjected to liquid shock loading. A series of experimental results on fully clamped aluminum alloy and mild steel rectangular plates of different thickness and varying standoff distance of hammer is reported. The effect of va...

This paper studies the dynamic plastic response of thin quadrangular mild steel plates subjected to uniform and localized impulsive loading. For this, two new dimensionless numbers based on dimensionless governing equation of plates have been suggested. Four different effective parameters such as plate geometry, inertia of applied load, mechanical...

The main purpose of this study is to show the metal plate forming by direct application of gas mixture detonation loads can be considered as an alternative high-velocity forming method for the structures instead of conventional one. Therefore, in this investigation, a series of experimental tests have been conducted on the aluminum alloy and mild s...

This paper describes an experimental setup consisting of a drop hammer and a shock tube filled with a liquid, where a shock wave is formed, and results of experiments performed with fully clamped rectangular plates subjected to an impact load of the water shock wave. The results are presented in terms of the central deflection of the plates as a fu...

In this paper, experimental responses of fully clamped aluminium and steel rectangular plates are presented subjected to hydrodynamic loading. The GMDHtype neural networks (Group Method of Data Handling) are then used for the modelling of the mid-point deflection thickness ratio of the rectangular plates using the experimental results. The purpose...

Drop hammer impact experiments have been carried out to assess the dynamic plastic response of fully clamped circular and rectangular plates made of aluminum and steel subjected to hydrodynamic impact loading at various energy levels. Also, the effective parameters in forming process are proposed in non-dimensional forms for modeling and prediction...

In this paper, empirical modelling of circular clamped plates subjected to impulsive loading is investigated. Plates are formed by detonation of a mixture of Oxygen and Acetylene in a combustion chamber with different volume ratios. The purpose of empirical modelling is to demonstrate how some parameters such as mechanical properties of plate and g...

Proposing a comprehensive model to predict the fatigue life of composite structures under dynamic loading has always been a challenging problem. In this study, an attempt has been made to develop a polynomial model by utilization of experimental data together with singular value decomposition technique to estimate the fatigue life of composite mate...

This study introduces an empirical analysis approach to assess mechanical behavior of thin circular mild steel plates subjected to uniform and localized impulsive loading. The empirical models have been derived by singular values decomposition procedure to predict midpoint deflection of circular plates. The essence of empirical analysis is based on...

The purpose of this work is to perform an experimental study and also modeling the plastic deformation of rectangular plates under a low-rate impact loading by the drop hammer system. In the experimental section, some experiments are conducted on the rectangular plates with different levels of energy to survey the mechanical behavior of the steel a...

In this paper, the plastic deformation of clamped rectangular steel plates is investigated both experimentally and numerically using gases mixture detonation approach. In the experimental tests, the steel plates with various thicknesses were deformed under shock wave effect caused by high velocity rate explosion. Also, the pressure of gases mixture...

In this paper, process of dynamic powder compaction is investigated experimentally using impact of drop hammer and die tube. A series of test is performed using aluminum powder with different grain size. The energy of compaction of powder is determined by measuring height of hammer and the results presented in term of compact density and rupture st...

In this paper, process of dynamic powder compaction is inves tigated experimentally using impact of drop hammer and die tube. A series of test is performed using aluminum powder with different grain size. The energyof compaction of powder is determined by measuring height of hammer and the results presented in term of compact density and rupture s...

Nowadays due to increasing industrial utilization of shock waves, it became popular to use analytical, numerical modeling and experimental tests to evaluate effect of shock waves on metal deformation. To explain this effect on metal properties, current paper considers both experimental and numerical plastic deformation of clamped rectangular steel...

Although wings of insects show a large variation in morphology, they are all made from a network of irregular veins interconnected through membranous areas. Depending on their shape, size, and position, wing veins are usually divided into three different groups: longitudinal veins, cross-veins and ambient veins. The veins together with the membrane...

A series of experimental results on thin mild steel plates clamped at the boundary subjected to gas detonation shock loading are presented. Detonation occurred by mixing Acetylene (C2H2)-Oxygen (O2) in various volume ratio and different initial pressure. The applied impulse is varied to give deformation in the range from 6 mm to 35 mm. Analytical m...

This paper describes the experimental setup of combustion chamber, and the shock loads resultant of gases mixture detonation. The results of experiments performed with fully clamped circular steel plates subjected to detonation of acetylene (C 2 H 2)–oxygen (O 2) in various volume ratio and different initial pressure. The energy of deformation of p...

The exceptional mechanical performance and outstanding material properties of biological structures have attracted much attention during recent decades. Finite Element (FE) Method is one of the most useful tools for investigating the eeects of diierent parameters on the mechanical behaviour of such complex structures. This method, however, presents...

In this paper, forming of fully clamped circular plate by using low velocity impact system has been investigated. This system consists of liquid shock tube and gravity drop hammer. A series of test on mild steel and aluminum alloy plates has been done. The effect of varying both impact load and the plate material on the deflection are described. Th...

In this paper, the plastic deformation of fully clamped circular plates is investigated, under different blast loadings by means of the ballistic pendulum. Experimental results extracted from experiments, are evaluated according to the mid-point deflection of the plate as well as the deformation profile. In order to assess the effects of materials...

The aim of this paper is to investigate the green density, the percentage of porosity and the density distribution of materials which have been produced by powder compaction procedure under low rate impact loading by using drop hammer both experimentally and analytically. Effect of grain size and different level of energy on density is carried out...

The purpose of this paper is to investigate those products which are produced by powder compaction procedure under the low rate impact loading by a drop hammer, both theretically and numerically. Experimental section includes checking the efficiency of density, bending strength and elasticity modulus of the product from grain size and different lev...

The main aim of this paper is to perform analytical and experimental study on the inelastic deformation of fully clamped rectangular plates under the low rate hydrodynamic loading with drop-hammer. In the analytic section, some models are presented for predicting the mid-point deflection by two methods, namely the plastic hinge and energy method. T...

In this paper, plastic deformation of the clamped mild steel and aluminum circular plates subjected to different hydrodynamic impact loading conditions are investigated. Extensive experimental tests were carried out by using a drop hammer. The experimental results presented in terms of central deflection of the plates, deflection profiles, and stra...