An Experimental Crack Propagation Analysis of Aluminum Matrix Functionally Graded Material

In this study, a functionally graded cylindrical specimen was obtained via centrifugal casting and its fatigue crack behavior was investigated. Aluminum 2014 alloy and SiC were used as matrix material and ceramic particle, respectively. The distribution of SiC and the mechanical properties of material through cylinder wall thickness were varied because of the centrifugal force during centrifugal casting. Variations in microstructure and hardness were examined. A cylindrical specimen was cut through its thickness in four sections through vertical slicing. Tensile strength was tested on each section to determine the mechanical properties that can be varied such as Young’s modulus, tensile strength, and yielding stress. To investigate the effect of variation in the mechanical properties and distribution of SiC particles on fatigue crack behavior, fatigue crack growth tests were applied under tensile cyclic load with stress ratio R = 0.1. The samples were prepared in three separate groups: central notched, single-edge notched on SiC-rich side, and single-edge notched on aluminum-rich side. It was found that SiC distribution affected fatigue crack initiation and propagation. The fatigue life increased up to 350% because of increasing SiC ratio for central notched specimens. Cracks were started out later on the single-edge notched SiC-rich side compared to aluminum-rich side whose fatigue life increased up to 500%. In addition, it was found that unreinforced aluminum material’s fatigue life was lower than that of reinforced material

CALCULATION OF STREES CONCENTRATION FACTOR ON THE ORTHOTROPIC ROLLER CHAIN LINK PLATE

The stress concentration factors for transmission roller chain link plates made of isotropic and orthotropic composite materials have been calculated used the finite element method. The stress concentration factors investigated for three different composite materials (fiber-glass, boron-epoxy, graphite-epoxy) and isotropic roller chain link plate and three different geometry. The composite materials of reinforcement angles are fixed 0 and 90 degree. The stress concentration factors the made of different composite materials and several geometry have been compared and controlled by the fotoelastic experiment

A COMPUTER PROGRAM FOR ELASTO-PLASTIC STRESS ANALYSIS IN PLANE

In this study, the structure of computer program which solves the elastic and elasto-plastic stress analysis of machine elements that are manufactured isotrop materials or metal -matrix composites materials by using the finite element method, have been explained. An isoparametric rectangular element with nine nodes have been taken and Lagrange polynomials have been used as interpolation function. A computer program has been developed which solves the linear equation systems accurately by using optimum time and computer memory. In the calculation of plastic zone stress analysis initial stress method has been used. Two example solutions have been given for the related program. Fortran has been used as a program language

A METHOD FOR FINITE ELEMENT MESH GENERATION FOR 2-D PROBLEMS

The first step in numerical analysis techniques is the preparation of a suitable mesh for solution domain. In the finite element method, the mesh generation, as a preprosessing stage, affects the accuracy of the results importantly. Furthermore, it is very time consuming when it is not carried out automatically. In this study, an automatic mesh generation technique which can be used for plane and axisymmetric problems is introduced. Meshes prepared with this technique for several geometries are given. With the computer program developed for this study, the desired domains can be divided into 3 node triangular and 4, 8 and 9 node quadrilateral elements with least input information and suitably fine meshes

ELASTO-PLASTIC STRESS ANALYSIS OF COMPOSITE PLATES WITH QUADRILATERAL HOLES

In this study, elasto-plastic stress analysis have been made for composite plates containing a central hole subjected to uniaxial tension under various uniformly distributed loads. In the solution, ısoparametric quadrilateral elements with nine nodes have been used. For different geometries of the holes and 0 and 90 degrees reinforcement angles, residual stress variations have been investigated

SOLUTION OF TRANSIENT HEAT CONDUCTION PROBLEM BY THE FINITE ELEMENT METHOD

Determination of temperature distribution is generally the first step in the design of machine elements subjected to ubnormal temperatures in their service life and for selection of materials. During this heat transfer analysis, the boundary and enviromental conditions must be modeled realistically and the geometry must be well represented. A variety of materials deviating from simple constant property isotropic material to composit materials having different properties according to direction of reinforcements are to be analysed. Then, the finite element method finds a large application area due to its use of same notation in heat transfer analysis and mechanical analysis of elements. In this study, the general formulation of two dimensional transient heat conduction is developed and a sample solution is given for arectangular bar subjected to convection baundary condition

STRESS ANALYSIS UNDER PRESS - FIT CONDITION IN THE MACHINE ELEMENT MADE OF COMPOSITE MATERIALS

Transfer of the power and motion, shaft-pulley systems is combined different forms. One of them is press fit. In this study, under the inner pressure occurred at the press-fit condition pulley was investigated by the analytic and finite elements methods. In this investigation, the diameter at the shaft (d) and outer diameter (D) ratio was changed with respect to each other in order to investigate stress distribution change. In addition to d/D ratio, computing occurring of stress at the different tightness, the optimum tightness gap was investigated. The fournode isoparametric finite element is used as the solution method. Found result controlled with analytic solution.Now, from the space and automobile industry to food industry the widespread usage for the pulley that is made from metal matrix composite material (steel-aluminium) 0 and 90 degrees reinforcement condition and various tightness solution was made, the press fit condition at the composite was investigated

ANALYSIS OF RESIDUAL STRESS IN THE METAL MATRIX COMPOSITE PLATES WITH CIRCULAR HOLES

In this study, elasto-plastic stress analysis have been made for metal matrix composite plates containing a central hole subjected to uniaxial tension under various uniformly distributed loads. In the solution, ısoparametric rectangular elements with nine nodes have been used. In the reinforcement angles 0 and 90 degrees for different diameters of the holes ın the vicinity of the holes residual stress variations have been investigated

RESIDUAL STRESS ANALYSIS, WOVEN STEEL FIBER REINFORCED THERMOPLASTIC COMPOSITE CANTILEVER BEAM LOADED BY A CONSTANT SINGLE FORCE AT ITS FREE END

In this study an elastic-plastic stress analysis is carried out in a woven steel fiber reinforced thermoplastic composite cantilever beam loaded by a constant single force at its free end. The expansion of the plastic region and the residual stress compenent of ?x are determined 0, 15, 30 and 45 orientation angles. Yielding begins for 0 and 45 orientation angles both of upper and lower surfaces of the beam at the same distances from the free end. An elastic-plastic analysis is carried out for the plastic region which spreads at the upper and lower surfaces together. The residual stress compenents are obtained after releasing the external force. The distributions of the residual stress compenents of ?x are also determined. The intensity of the residual stress compenents of ?x is maximum at the upper or lower surfaces of the beam