Predicting the Impact of Quenching on Mechanical Properties of Complex-Shaped Aluminum Alloy Parts

1995 ◽  
Vol 117 (2) ◽  
pp. 479-488 ◽  
Author(s):  
D. D. Hall ◽  
I. Mudawar

The mechanical properties of age-hardenable aluminum alloy extrusions are critically dependent on the rate at which the part is cooled (quenched) after the forming operation. The present study continues the development of an intelligent spray quenching system, which selects the optimal nozzle configuration based on part geometry and composition such that the magnitude and uniformity of hardness (or yield strength) is maximized while residual stresses are minimized. The quenching of a complex-shaped part with multiple, overlapping sprays was successfully modeled using spray heat transfer correlations as boundary conditions within a finite element program. The hardness distribution of the heat-treated part was accurately predicted using the quench factor technique; that is, the metallurgical transformations that occur within the part were linked to the cooling history predicted by the finite element program. This study represents the first successful attempt at systematically predicting the mechanical properties of a quenched metallic part from knowledge of only the spray boundary conditions.

2021 ◽  
Vol 37 ◽  
pp. 205-215
Author(s):  
Heng Chen ◽  
Hongmei Cheng ◽  
Aibin Xu ◽  
Yi Xue ◽  
Weihong Peng

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration and accumulation. Exploring the evolution law of fracture field of coal and rock mass under the condition of drilling and slitting construction has important theoretical significance for guiding efficient gas drainage. The generation and evolution process of coal and rock fissures is also the development and accumulation process of its damage. Therefore, based on damage mechanics and finite element theory, the mathematical model is established. The damage variable of coal mass is defined by effective strain, the elastoplastic damage constitutive equation is established and the secondary development of finite element program is completed by FORTRAN language. Using this program, the numerical simulation of drilling and slitting construction of the 15-14120 mining face of Pingdingshan No. 8 Mine is carried out, and the effects of different single borehole diameters, different kerf widths and different kerf heights on the distribution area of surrounding coal fracture field and the degree of damage are studied quantitatively. These provide a theoretical basis for the reasonable determination of the slitting and drilling arrangement parameters at the engineering site.


2020 ◽  
Vol 21 (1) ◽  
pp. 147-156
Author(s):  
Fred Thomas Tracy ◽  
Jodi L. Ryder ◽  
Martin T. Schultz ◽  
Ghada S. Ellithy ◽  
Benjamin R. Breland ◽  
...  

The purpose of this research is to compare the results from two different computer programs of flow analysesof two levees at Port Arthur, Texas where rising water of a flood from Hurricane Ike occurred on the levees. The first program (Program 1) is a two-dimensional (2-D) transient finite element program that couples the conservation of mass flow equation with accompanying hydraulic boundary conditions with the conservation of force equations with accompanying x and y displacement and force boundary conditions, thus yielding total head, x displacement, and y displacement as unknowns at each finite element node. The second program (Program 2) is a 2-D transient finite element program that considers only the conservation of mass flowequation with its accompanying hydraulic boundary conditions, yielding only total head as the unknown at each finite element node. Compressive stresses can be computed at the centroid of each finite element when using the coupled program. Programs 1 and 2 were parallelized for high performance computing to consider thousands of realisations of the material properties. Since a single realisation requires as much as one hour of computer time for certain levees, the large realisation computation is made possible by utilising HPC. This Monte Carlo type analysis was used to compute the probability of unsatisfactory performance for under seepage, through seepage, and uplift for the two levees. Respective hydrographs from the flood resulting from Hurricane Ike were applied to each levee. When comparing the computations from the two programs, the most significant result was the two programs yielded significantly different values in the computed results in the two clay levees considered in this research.  


Author(s):  
Makoto Tanabe ◽  
Hajime Wakui ◽  
Nobuyuki Matsumoto

Abstract A finite element formulation to solve the dynamic behavior of high-speed Shinkansen cars, rail, and bridge is given. A mechanical model to express the interaction between wheel and rail is described, in which the impact of the rail on the flange of wheel is also considered. The bridge is modeled by using various finite elements such as shell, beam, solid, spring, and mass. The equations of motions of bridge and Shinkansen cars are solved under the constitutive and constraint equations to express the interaction between rail and wheel. Numerical method based on a modal transformation to get the dynamic response effectively is discussed. A finite element program for the dynamic response analysis of Shinkansen cars, rail, and bridge at the high-speed running has been developed. Numerical examples are also demonstrated.


2017 ◽  
Vol 63 (4) ◽  
pp. 51-69
Author(s):  
A. Zbiciak ◽  
M. Ataman ◽  
W. Szcześniak

AbstractThis paper presents the capabilities of ABAQUS finite-element program [1] in modelling sandwich beams and plates resting on deformable foundations. Specific systems of sandwich beams and plates separated by an elastic core layer were subjected to the action of point and distributed moving loads. A few theoretical examples are provided to present different techniques of modelling the foundations and the moving loads. The effects of the boundary conditions and of the foundation parameters on the deflections of the analysed structures are also presented.


2021 ◽  
Vol 11 (6) ◽  
pp. 2661-2678
Author(s):  
Raquel Oliveira Lima ◽  
Leonardo José do Nascimento Guimarães ◽  
Leonardo Cabral Pereira

AbstractThis paper presents a coupled finite element approach for modeling geomechanical effects induced by production/injection processes in petroleum reservoirs. The module developed employs coupled- reservoir analysis using CMG IMEX® as the flow simulator and a finite element program in MATLAB® as the stress–strain simulator, in a two-way explicit partial coupling scheme. The flow and mechanical problems are coupled by the change of effective stress due to the change in pore pressure and by varying stress-dependent reservoir properties, such as pore compressibility, absolute permeability, and porosity. The coupling procedure was applied to the Namorado Field (Campos Basin, Brazil) to quantify the impact of the rock deformation on fluid recovery. Based on the cases studied, the coupled analyses predicted higher oil recovery than the conventional reservoir simulations. The results showed that the reservoir deformation can affect its performance and must be taken into account in reservoir-engineering studies depending on production strategy and reservoir stiffness. Besides, the geomechanical calculations were performed only in the coupling timesteps, reducing the computational effort and making this coupling method feasible on a field scale.


2010 ◽  
Vol 146-147 ◽  
pp. 724-728
Author(s):  
Wen Juan Yao ◽  
Bao Lin Hu ◽  
Ting Chen Fang

Materials with different modulus in tension and compression have a wide application in engineering practice, especially the composite materials developed in recent years, which have properties of different tension-compression modulus. To exploring the general features of mechanical properties of structures with different modulus, the dimensionless equation of finite element was deduced for structure with different modulus, and corresponding finite element program was developed .the stresses of the cantilever beam by program of the theory with different modulus. The impacts on member stresses resulted from the change of structure size, external load and the ratio of different modulus are compared and analyzed. Finally, we have drawn a conclusion that the property of different modulus of the material is very important to its stress, and have given out suggestions on the optimization of state of structural stress.


Author(s):  
P. M. A. Areias ◽  
R. M. Natal Jorge ◽  
J. T. Barbosa ◽  
A. A. Fernades ◽  
T. Mascarenhas ◽  
...  

In this paper, mechanical properties of human skin are inferred from the information of a suction test using a cutometer test. Experiments with a 2 mm probe are carried out and numerical tests using a finite element program developed by the first author are employed for comparison. Regarding the numerical tests, both axisymmetric and complete 3D models of a silicon sheet were employed with the hyperelastic Yeoh constitutive model.


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