High speed and absence of a precise control over pressure distribution confine sheet ELECTROMAGNETIC FORMING into a die to simple shapes having shallow depth. It is possible to reach a higher depth by using a convex punch instead of a concave die. In this study, sheet ELECTROMAGNETIC FORMING on a punch and sheet ELECTROMAGNETIC FORMING into a die are investigated. The ELECTROMAGNETIC part of the study is investigated analytically and its mechanical part is studied numerically. In order to couple ELECTROMAGNETIC with mechanical parts, no-coupling method is used. The obtained results are verified by comparing the obtained results with previous experimental ones in literature. Rate-dependent and rate-independent hardenings are taken into consideration for the mechanical behavior for material of AAl1050. Using appropriate hardening model for material yields acceptable results. Moreover, a convex punch instead of a concave die is used to reach to a higher depth in sheet ELECTROMAGNETIC FORMING.

Tube FORMING is a common FORMING process in industry. There are several methods in tube FORMING, whereas industries are looking for best methods with low cost and high speed. For this reason, industries need new modern FORMING methods. ELECTROMAGNETIC FORMING and tube hydroFORMING are two modern processes which are used in manufacturing of hollow complex parts. These two processes are considered as high speed FORMING methods in automotive industries. In this paper, the processes of ELECTROMAGNETIC FORMING of tubes and high speed hydroFORMING of tubes have been investigated by numerical simulations and empirical method. Firstly, the results of numerical solutions by ABAQUS software are compared with empirical tests. At last these two FORMING methods have been compared in terms of displacement, stress distribution and thickness distribution. The results of deformation and thickness of the tip of the bulged tubes in empirical tests are in good agreement with the results of numerical simulations of this research. The results show that formability and bulge height in ELECTROMAGNETIC FORMING process are higher than high speed hydroFORMING. However, high speed hydroFORMING may be used in applications such as shirring fitting of parts and rings on tubes instead of ELECTROMAGNETIC FORMING.

The coupling of the ELECTROMAGNETIC field and the mechanical structure field is one of the main problems in the theoretical study of ELECTROMAGNETIC FORMING (EMF). In this study, two possible approaches for the simulation of the ELECTROMAGNETIC tube compression FORMING process were implemented and compared: A loose-coupled and a sequential-coupled algorithm. In the loose-coupled the ELECTROMAGNETIC field and mechanical structure field were solved separately, but in the sequential-coupled algorithm, the ELECTROMAGNETIC simulation and the mechanical structure simulation were iteratively performed by using Maxwell equations and Finite Difference Method (FDM) as subroutine VDLOAD in ABAQUS software. A deformation of the tube and consequently a change in inductance of tube during the process in the sequential-coupled algorithm was considered. The depth of bead in loose-coupled algorithm compared to experimental result had a 35% error, but in a sequential-coupled algorithm this error has been reduced to 5%. To predict tearing in this process Johnson-Cook damage criterion used. Increasing of discharge voltage and tube thickness respectively, had maximum effect on Johnson-Cook damage. Amount of damage less than 0.8 is conservatively suitable for the safe area without fracture.

ELECTROMAGNETIC FORMING is a high energy rate FORMING process which is applied for manufacturing and assembly of many parts that are used in automobile and aerospace industries. In this process, the ELECTROMAGNETIC body forces (Lorentz forces) are used to produce metallic parts. Joining high electrical conductivity parts by using ELECTROMAGNETIC FORMING process is as an innovative method. In this research work, the effect of important parameters of process such as discharge voltage, radius and width of rectangular groove on the strength of assembled products were studied by using finite element method and design of experiment. After introducing the governing equations, the output of these equations were applied in simulation as a pressure on work-piece. In this simulation, an axisymmetric model was used in analysis and Johnson-Cook theory was applied due to high strain rate to show the plastic behavior of materials. Finally, the numerical results were compared with the results reported by other researchers. As a result, the contact surface at bottom of the groove increases with the increase of the voltage energy and more filling groove, increasing strength of joint. Also Strength of joint increases, due to create partial shearing of the tube at the groove edge and interference stresses at the tube and mandrel interface.

Determining capacitance and coil parameter in ELECTROMAGNETIC FORMING (EMF) process is one of the common difficulties in industrial applications of the process. In the present paper, an algorithm has been presented in order to calculate EMF device electrical current pulse with various capacitances and coil parameters. At first, an initial guess is considered for angular frequency and capacitance. Then, the effective part of the current pulse is calculated by an iterative computational subroutine using FE method. In this paper, an ELECTROMAGNETIC tube expansion problem, previously analyzed experimentally in the literature, has been studied. The comparison shows an acceptable agreement between numerical and experimental results.

ELECTROMAGNETIC FORMING is a high energy rate FORMING process which is applied for manufacturing and assembly of many parts that are used in automobile and aerospace industries. In this process, the ELECTROMAGNETIC body forces (Lorentz forces) are used to produce metallic parts. In this article, the influence of important process parameters such as discharge voltage, friction coefficient, clearance between the tube and die, wall thickness and length of tube, on the radial displacement and workpiece thinning were investigated. The output of governing equations in the form of pressure applied on the part via a subroutine in a Fortran Program. A dynamic analysis using two dimensional axisymmetric models were performed and Johnson-Cook theory was applied to represent the effect of strain rate sensitivity and show the plastic behavior in the deformation process. Finally, the numerical results were compared with the results reported by other researchers and found a good agreement between them.

ELECTROMAGNETIC FORMING is a high energy rate FORMING process which is applied for manufacturing and assembly of many parts that are used in automobile and aerospace industries. In this process, the ELECTROMAGNETIC body forces (Lorentz forces) are used to produce metallic parts. In this article, the influence of important process parameters such as discharge voltage, friction coefficient, clearance between the tube and die, wall thickness and length of tube, on the radial displacement and workpiece thinning were investigated. The output of governing equations in the form of pressure applied on the part by using a subroutine in a Fortran Program. A dynamic analysis using two dimensional axisymmetric models were performed and Johnson-Cook theory was applied to represent the effect of strain rate sensitivity and show the plastic behavior in the deformation process. Finally, the numerical results were compared with the results reported by other researchers and found a good agreement between them.

In FORMING conical parts by traditional deep drawing techniques, due to the stress concentration at the contact area between the punch and the workpiece, thinning and rupture occurs on the sheet. There is also a high possibility of wrinkling in the free area of the sheet; where there is no contact between the punch and the sheet. Therefore, new methods have been examined in FORMING this group of parts. ELECTROMAGNETIC FORMING is one of the relatively old methods of high-speed FORMING that has attracted more attention in recent years. In the present study, the process of pre-FORMING of aluminum conical parts using ELECTROMAGNETIC force has been discussed numerically and experimentally. First, experiments were carried out by a simple spiral coil and after confirming the validity of the numerical simulations, the effect of ELECTROMAGNETIC force density in radial and axial directions was investigated in different areas of the sheet. Using the obtained results, a new coil was designed and built that has the ability to provide suitable distribution of the force in the radial and axial directions. Reduction in power consumption by up to a quarter, an increase in the amount of radial inward force and the height of the preform formed cone up to 2 times, minimizing the friction force, reduction of the workpiece center thinning by 3% (while increasing the height by 2 times) and elimination of wrinkles in the flange area of the sheet are the advantages of using the new coil compared to the primary coil.

ELECTROMAGNETIC FORMING is a high energy rate FORMING process applied for manufacturing and assembly of many parts that are used in automobile and aerospace industries. In this process, the ELECTROMAGNETIC body forces (Lorentz forces) are used to produce metallic parts. Joining high electrical conductivity parts by using ELECTROMAGNETIC FORMING process is an innovative method. Therefore, it is very important to use a proper technique to ensure the quality of the Strength of ELECTROMAGNETIC Joints. In this article, this process was simulated in ABAQUS. Then geometric, physical and mechanical specifications of the tube and coil are entered to subroutine and the magnetic pressure is obtained; by applying them on tube in ABAQUS software, agent analysis of the process and deformation of the work-piece is obtained. The effective process parameters such as discharge voltage, clearance between the tube and die, wall thickness and length of the tube on depth of bead were experimentally investigated by design of experiment technique based on Taguchi Method and signal to noise. Finally, very good agreement was found between simulation and experimental results. The depth of bead in sequential coupled algorithm compared to experimental result had about 4% error.