scholarly journals Prioritization of Process Parameters for an Efficient Optimisation of Additive Manufacturing by Means of a Finite Element Method

Procedia CIRP ◽  
2013 ◽  
Vol 12 ◽  
pp. 169-174 ◽  
Author(s):  
T.A. Krol ◽  
C. Seidel ◽  
M.F. Zaeh
2010 ◽  
Vol 34-35 ◽  
pp. 641-645
Author(s):  
Hong Shuang Zhang

In order to fully understanding the distribution of residual stress after riveting and the relationship between residual stress and riveting process parameters during riveting, Finite Element Method was used to establish a riveting model. Quasi-static method to solve the convergence difficulties was adopted in riveting process. The riveting process was divided into six stages according to the stress versus time curves. The relationship of residual stress with rivet length and rivet hole clearance were established. The results show numerical simulation is effective for riveting process and can make a construction for the practical riveting.


Membranes ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 139
Author(s):  
Tuba Yaqoob ◽  
Muhammad Ahsan ◽  
Arshad Hussain ◽  
Iftikhar Ahmad

There is an enormous need in the health welfare sector to manufacture inexpensive dialyzer membranes with minimum dialysis duration. In order to optimize the dialysis cost and time, an in-depth analysis of the effect of dialyzer design and process parameters on toxins (ranging from tiny to large size molecules) clearance rate is required. Mathematical analysis and enhanced computational power of computers can translate the transport phenomena occurring inside the dialyzer while minimizing the development cost. In this paper, the steady-state mass transport in blood and dialysate compartment and across the membrane is investigated with convection-diffusion equations and tortuous pore diffusion model (TPDM), respectively. The two-dimensional, axisymmetric CFD model was simulated by using a solver based on the finite element method (COMSOL Multiphysics 5.4). The effect of design and process parameters is analyzed by solving model equations for varying values of design and process parameters. It is found that by introducing tortuosity in the pore diffusion model, the clearance rate of small size molecules increases, but the clearance rate of large size molecules is reduced. When the fiber aspect ratio (db/L) varies from 900 to 2300, the clearance rate increases 37.71% of its initial value. The results also show that when the pore diameter increases from 10 nm to 20 nm, the clearance rate of urea and glucose also increases by 2.09% and 7.93%, respectively, with tolerated transport of albumin molecules.


2008 ◽  
Vol 07 (01) ◽  
pp. 21-32
Author(s):  
T. S. YANG ◽  
N. C. HWANG ◽  
R. F. SHYU

Deep drawing process, one of sheet metal forming methods, is very useful in industrial field because of its efficiency. The deep drawing process is affected by many material and process parameters, such as the strain-hardening exponent, plastic strain ratio, anisotropic property of blank, friction and lubrication, blank holder force, presence of drawbeads, the profile radius of die and punch, etc. In this paper, a finite element method is used to investigate the cylindrical deep drawing process. The thickness of product and the forming force predicted by current simulation are compared with the experimental data. A finite element method is also used to investigate the maximum forming load and the minimum thickness of products under various process parameter conditions, including the profile radius of die, the clearance between die cavity and punch and the blank holding force. Furthermore, the material anisotropy and process parameters effect on the earing are also investigated.


2012 ◽  
Vol 531-532 ◽  
pp. 746-750
Author(s):  
Xue Wen Chen ◽  
Ze Hu Liu ◽  
Jing Li Zhang

The main causes of performance variation in tube bending process are variations in the mechanical properties of material, initial tube thickness, coefficient of friction and other forming process parameters. In order to control this performance variation and to optimize the tube bending process parameters, a robust design method is proposed in this paper for the tube bending process, based on the finite element method and the Taguchi method. During the robust design process, the finite element analysis is incorporated to simulate the tube bending process and calculate the objective function value, the orthogonal design method is selected to arrange the simulation experiments and calculate the S/N ratio. Finally, a case study for the tube bending process is implemented. With the objective to control tube crack (reduce the maximum thinning ratio) and its variation, the robust design mathematical model is established. The optimal design parameters are obtained and the maximum thinning ratio has been reduced and its variation has been controlled.


Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2568 ◽  
Author(s):  
Jinqiang Ning ◽  
Daniel E. Sievers ◽  
Hamid Garmestani ◽  
Steven Y. Liang

Metal additive manufacturing can produce geometrically complex parts with effective cost. The high thermal gradients due to the repeatedly rapid heat and solidification cause defects in the produced parts, such as cracks, porosity, undesired residual stress, and part distortion. Different techniques were employed for temperature investigation. Experimental measurement and finite element method-based numerical models are limited by the restricted accessibility and expensive computational cost, respectively. The available physics-based analytical model has promising short computational efficiency without resorting to finite element method or any iteration-based simulations. However, the heat transfer boundary condition cannot be considered without the involvement of finite element method or iteration-based simulations, which significantly reduces the computational efficiency, and thus the usefulness of the developed model. This work presents an explicit and closed-form solution, namely heat sink solution, to consider the heat transfer boundary condition. The heat sink solution was developed from the moving point heat source solution based on heat transfer of convection and radiation. The part boundary is mathematically discretized into many heats sinks due to the non-uniform temperature distribution, which causes non-uniform heat loss. The temperature profiles, thermal gradients, and temperature-affected material properties are calculated and presented. Good agreements were observed upon validation against experimental molten pool measurements.


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