International Journal of Advanced Design and Manufacturing Technology
Volume:1 Issue: 1, 2008

In design and optimization process of laminated composite structures, the number of layers, layer angles, stacking sequence, material types etc should be specified. Each of aforesaid parameters can be applied as a design variable. In this paper, the target is to minimize the weight of laminated composite pin loaded structures. The laminated composite structures are designed based on the load of pin. Pin mounting in laminated composite plates causes stress concentration around the hole of pin. In this research, the programming facility of FE software (ANSYS) is used for design and optimization of laminated plate. Constrains of minimization problem is based on Tsai-Wu criterion. The pin loaded plate is divided to two regions: the around of hole and far away from hole. The optimization process is solved concurrently and interactively for two regions. The selected stacking sequences are the quasi isotropic, cross ply and angel ply. The target is to obtain a configuration with accessible number of plies. For this reasom the branch and bound method was used. The obtained results show that the quasi isotropic plate is stronger than cross ply plate and cross ply plate is stronger than angle ply plate. However, this order is reversed in a special load. In the other words, the cross ply plate is being stronger than quasi isotropic plate in this case. In this paper also effect of geometric parameters over the strength of pin loaded plates are investigated.

In this paper, multi-stage optimum design of composite pressure vessels is presented. The design variables for composite vessels include the head shape, the winding angle, the layer thickness, the number of layers, and the stacking sequence. A parameter called modified shape factor is introduced as an objective function. This parameter takes into account the effects of the internal pressure and volume, the vessel weight, and the composite material properties. The proposed algorithm uses genetic algorithm and finite element analysis to optimize the design parameters. As a few examples, this procedure is implemented on geodesic and ellipsoidal heads. The results show that for the given vessel conditions, the geodesic head shape with helical winding angle of nine degrees has the better performance

In this paper, chaotic motion analysis and its control for a non-planar non-linear cantilever beam with axial and lateral parametric excitation in the free end is accomplished. This is a new method for control of chaotic motion of a non-linear planar beam. In this survey, internal resonance of the beam is 2:1, the initial resonance is in the outside of plane, and it is assumed a sub-resonance for inner plane. The beam is modeled with Lagrange method. Then, multi comparison method is used for system transformation of parametric and external excitation to the averaged equation where the constant load applied to them. Finally, with the usage of numerical simulation, an open loop control is designed for chaotic motion of non-planar cantilever beam, which excited in the free end to reduce the beam vibration in one axis. The results are presented in the curves to show the limit of stability

The subject we discussion about are Nucleation and Meta stable phenomena’s, superheat liquids, super cold liquids and meanwhile applications of this liquids. all in all Meta stable situation can occur in three condition: First while changing liquid phase to gas phase by heating, Second changing liquid phase to solid phase by cooling, Third while moving water stream in subsonic nozzles or supersonic nozzles before condensation process occur. Of curse, first and second conditions more than third condition view in nature and various industrials and productions of engender in first and second conditions are more than third condition. Of curse, skews and turbulences that explain about them can disassemble these conditions. Meanwhile getting relations show that superheat degree have maximum and minimum amount.

The numerical method presented by Safaiy et al. [1] is reformulated with Finite Volume method in its most general form and tested on non-orthogonal flow problems. Navier-Stokes equations are solved for the solution of stream function and Vorticity. Numerical solutions of the driven skewed cavity flow, solved using a fine grid (513×513) mesh, are presented for Reynolds number of 100 and 1000 for skew angles ranging between. The results are compared with the numerical solutions found in the literature and also with analytical solutions as well

In this paper, we use Molecular Dynamics and Finite Element Simulations to determine the mechanical properties of single-crystal metal of silver (Ag) with nano-holes. The Lattice Transition method from 3-dimensions into 2-dimentions in molecular dynamics simulation as well as plane stress model in finite element method is used to lessen the simulation time consuming. Elasticity module reduction due to the existence of holes, their shape and configuration types has been studied. It can be seen that the manner in which the elasticity module is reduced in both the molecular dynamics and finite element simulations are the same; however, it is essential to serve an atomistic simulation to have more exact results

During last ten years, change of consumption pattern, variety and modernity of consumers, variety of producers and competitors, changes and vacillation rates, cause developing and decreasing the amounts of produce expenses by using hardware and software progressing, which are so important. In this respect, one of the possible solutions to increase the quality and enjoy the use of software possibilities is to perform producing systems. The aim of this article is to choose, automatic process and welding technology by using WELD-EXP. software. In this software, experience and knowledge of skilled men and expert form the rules in the expert system and knowledge base. After interchange of information and receive the necessary data from user, this software by studying and analyzing necessary instances, choose and suggest the best welding process or processes. Finally, the users confirm and complete it and present the welding process specification (WPS). Therefore, this way is time-consuming and save the expense of making and producing of weldments

In this research formability, behavior and texture of St14 low carbon steels produced by Foolad Mobarakeh plant for deep drawing application had been studied. Plate textures were characterized by X-ray Diffraction technique. To evaluate formability behavior one dimensional tensile test was carried out and related parameters were recognized. Moreover, Eriksson experiment and spherical pattern printing on samples were also implemented to scheme ultimate formability curve (FLD). Ultimate formability curve area was calculated using plane strain variations (FLD0). Effect of mechanical parameters on ultimate formability curve consist of yield strength, tensile strength, strain hardening coefficient, perpendicular anisotropy and texture were also studied. The results show that by increasing yield strength and tensile strength, lower area of ultimate formability curve decreases. In contrast, by increasing total elongation, strain hardening coefficient and perpendicular anisotropy parameter, plate formability has been enhanced