Numerical Optimization of Bearing Length in Composite Extrusion Processes

2008 ◽  
Vol 367 ◽  
pp. 47-54 ◽  
Author(s):  
Thomas Kloppenborg ◽  
Marco Schikorra ◽  
Michael Schomäcker ◽  
A. Erman Tekkaya

The decrease of the bearing length in extrusion processes results in increasing of the material flow and offers, through this, the possibility for manipulation and optimization. This paper presents a simulation based optimization technique which uses this effect for optimizing the material flow in direct extrusion processes. Firstly, the method is used in a multi-extrusion process with equal pitch circle profiles, then in an extrusion process of an asymmetric profile. Furthermore, a composite extrusion process is analyzed where endless wires of high strength steel are embedded in a base material of aluminum. The insertion of reinforcement elements into the base material flow, especially within the small ratio between profile thickness and the reinforcement diameter, can lead to significant local disturbances inside the die, which result in undesirable profile defects. Hence, the simulation-based optimization method is especially used to optimize inhomogeneous wall thicknesses in composite profiles.

2013 ◽  
Vol 585 ◽  
pp. 165-171 ◽  
Author(s):  
Stanka Tomovic-Petrovic ◽  
Rune Østhus ◽  
Ola Jensrud

Numerical analysis of the material flow during the extrusion process for high alloyed variants of the AA 6xxx series is presented in this paper. The analysis was performed by using the commercial FE code Forge2011®. Another issue considered in the paper was an interrelation between the die geometry and the critical extrusion process variables. For optimization of the die exit geometry, the model was produced with the use of linked equation in SolidWorks® combined with Mode FRONTIER. Several extrusion trials were performed to provide a basis for the verification of simulation results as extrusion temperature, speed and force. For the purpose, rods of a model alloy designated as AlMgSi4, based on an industrial AA6082 aluminium alloy with significantly higher silicon content, were extruded. A good correlation between measured and calculated results was obtained. This approach may enable simplifying when dealing with design of a new alloy.


2009 ◽  
Vol 83-86 ◽  
pp. 826-833 ◽  
Author(s):  
Thomas Kloppenborg ◽  
Alexander Brosius ◽  
A. Erman Tekkaya

The decrease of the bearing length in the aluminum extrusion processes results in an increase of the material flow and offers, through this, the possibility for correction and optimization. This study presents a simulation-based optimization technique which uses this effect for optimizing the material flow in a direct multi-hole extrusion process. First the extrusion process was numerically calculated to simulate the production of three rectangular profiles with equal cross sections. Here, the die orifices were arranged at various distances to the die centre, which lead to different profile exit speeds. Based on the initial numerical calculation, an automated optimization of the bearing length with the adaptive-response-surface-method was set up to achieve uniform exit speeds for all profiles. Finally, an experimental verification carried out to show the influence of the optimized die design.


Author(s):  
Leah Cuyler ◽  
Zeyi Sun ◽  
Lin Li

Electricity demand response is considered a promising tool to balance the electricity demand and supply during peak periods. It can effectively reduce the cost of building and operating those peaking power generators that are only run a few hundred hours per year to satisfy the peak demand. The research on the electricity demand response implementation for residential and commercial building sectors has been very mature. Recently, it has also been extended to the manufacturing sector. In this paper, a simulation-based optimization method is developed to identify the optimal demand response decisions for the typical manufacturing systems with multiple machines and buffers. Different objectives, i.e. minimizing the power consumption under the constraint of system throughput, and maximize the overall earnings considering the tradeoff between power demand reduction and potential production loss, are considered. Different energy control decisions are analyzed and compared regarding the potential influence on the throughput of manufacturing system due to the different control actions adopted by throughput bottleneck machine.


Author(s):  
Qian Wang ◽  
Lucas Schmotzer ◽  
Yongwook Kim

<p>Structural designs of complex buildings and infrastructures have long been based on engineering experience and a trial-and-error approach. The structural performance is checked each time when a design is determined. An alternative strategy based on numerical optimization techniques can provide engineers an effective and efficient design approach. To achieve an optimal design, a finite element (FE) program is employed to calculate structural responses including forces and deformations. A gradient-based or gradient-free optimization method can be integrated with the FE program to guide the design iterations, until certain convergence criteria are met. Due to the iterative nature of the numerical optimization, a user programming is required to repeatedly access and modify input data and to collect output data of the FE program. In this study, an approximation method was developed so that the structural responses could be expressed as approximate functions, and that the accuracy of the functions could be adaptively improved. In the method, the FE program was not required to be directly looped in the optimization iterations. As a practical illustrative example, a 3D reinforced concrete building structure was optimized. The proposed method worked very well and optimal designs were found to reduce the torsional responses of the building.</p>


2006 ◽  
Vol 10 ◽  
pp. 101-110 ◽  
Author(s):  
Marco Schikorra ◽  
Matthias Kleiner

The production of continuously reinforced profiles by use of aluminium as base material and a reinforcement made of steel or carbon offers a great potential for modern lightweight constructions. Within this scope, they present the potential for an increase in usage of space frame constructions in automotive or aerospace engineering. But with the insertion of reinforcement in the material flow of the extrusion process some problems can occur that are negligible in thee conventional extrusion processes: in the composite development area a significant local perturbation of the material flow is induced that can lead to the induction of high tensile stresses into the reinforcement. Due to this, failures like cracking of the reinforcement elements during the extrusion process has been detected in experimental investigations. A second problem occurring is the necessity of prediction of the seam weld position and prediction of the seam weld quality. The reinforcement can only be induced by bridge dies between two strands and due to this it is always positioned in a seam weld. While in conventional extrusion the seam weld positions is often only an aesthetical problem, now this position mainly influences the extruded profiles properties like moment of inertia. This paper deals with the problem of determination of seam weld position on the example of a double-t-profile extrusion. By use of a coupled thermo-mechanical finite element simulation with the commercial FE code HyperXtrude from Altair the velocity fields of an extrusion process with and without reinforcement were calculated and the resulting material flow was analysed. The numerical results went along with experimental investigations to verify the calculated results.


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