Goal driven optimization

Ph.DDOCTOR OF PHILOSOPH

Goal driven optimization of process parameters for maximum efficiency in laser bending of advanced high strength steels

Laser forming or bending is fast becoming an attractive option for the forming of advanced high strength steels (AHSS), due primarily to the reduced formability of AHSS when compared with conventional steels in traditional contact-based forming processes. An inherently iterative process, laser forming must be optimized for efficiency in order to compete with contact based forming processes; as such, a robust and accurate method of optimal process parameter prediction is required. In this paper, goal driven optimization is conducted, utilizing numerical simulations as the basis for the prediction of optimal process parameters for the laser bending of DP 1000 steel. A key consideration of the optimization process is the requirement for minimal microstructural transformation in automotive grade high strength steels such as DP 1000

Shape Optimization of Truck Wheel Hub

Import 03/08/2012Diplomová práce se zabývá tvarovou optimalizací náboje zadního kola. V první části je proveden popis zařízení, který slouží k sestavení výpočtového modelu. Na sestaveném výpočtovém modelu byla provedena statická analýza, která posloužila pro zjištění míst s největším namáháním. V další části byla provedena Tvarová optimalizace náboje(Shape optimization) a cílově řízená optimalizace (Goal driven optimization). V cílově řízené optimalizaci bylo cílem dosáhnout lepšího rozložení napětí po náboji tak, aby nedocházelo k překročení meze kluzu, a snížení hmotnosti náboje, čímž dojde ke snížení výrobních nákladů.This Master thesis is focused on shape optimization of the rear wheel hub. The first part deals with description of the device, which is used to build the computational model. Static analysis was performed on the model. This defined critical places. In the next part was made Shape optimization of the hub (Shape optimization), and target-guided optimization (Goal Driven Optimization). Goal-driven optimization provided out the parametrical model to three shape candidates. The candidates with the lowest stress was selected.337 - Katedra mechanikyvýborn

Goal Driven Optimization of Process Parameters for Maximum Efficiency in Laser Bending of Advanced High Strength Steels

Abstract. Laser forming or bending is fast becoming an attractive option for the forming of advanced high strength steels (AHSS), due primarily to the reduced formability of AHSS when compared with conventional steels in traditional contact-based forming processes. An inherently iterative process, laser forming must be optimized for efficiency in order to compete with contact based forming processes; as such, a robust and accurate method of optimal process parameter prediction is required. In this paper, goal driven optimization is conducted, utilizing numerical simulations as the basis for the prediction of optimal process parameters for the laser bending of DP 1000 steel. A key consideration of the optimization process is the requirement for minimal microstructural transformation in automotive grade high strength steels such as DP 1000

Design optimization of three dimensional geometry of wind tunnel contraction

AbstractThe aim of the present study is to redesign three dimensional geometry of existing open circuit wind tunnel contraction. The present work achieves the recommended contraction ratio, maximum uniformity at the working section mid-plane, without separation, no Gortler vortices in the contraction, and minimizing the boundary layer thickness at entrance to the working section. Using CFD along with optimization tools can shorten the design optimization cycle time. Moreover CFD allows insight into the minute flow details which otherwise are not captured using flow bench tests. The design exploration algorithm is used to optimize the profile of the contraction in an automated manner. The optimization is based on using screening method to choose the best design set and verified by the CFD solver. The new contraction, compared to the old design contraction is confirmed using CFD. The new design is manufactured in full scale. The optimized contraction is investigated computationally and experimentally

Optimization of process parameters in laser transmission welding for food packaging applications

Plastics’ joining is used widely in food processing applications for the packaging of increasingly diverse food products. Laser transmission welding is an attractive proposition for such applications as it can significantly reduce tooling costs and potential downtime at product changeovers. In order to fulfil this promise in an industrial environment, an effective means of process parameter prediction is required. In this paper, goal driven optimization is conducted, utilizing numerical simulations as the basis for the prediction of optimal process parameters for the laser transmission welding of polyethylene film to a polypropylene substrate. A key consideration of the optimization process is the requirement for specific, pre-defined bonded track widths

Delivery actuator for a transcervical sterilization device

The use of delivery systems in the human body for positioning and deploying implants, such as closure devices, dilation balloons, stents, coils and sterilization devices, are gaining more importance to preclude surgical incisions and general anesthesia. The majorities of the non-surgical medical devices are delivered in a low profile into human body form and subsequently require specialized operations for their deployment and release. An analogous procedure for permanent female sterilization is the transcervical approach that does not require either general anesthesia or surgical incision and uses a normal body passage. The objective of this paper is to detail the design, development and verification of an ergonomic actuator for a medical application. In particular, this actuator is designed for the deployment and release of an implant to achieve instant permanent female sterilization via the transcervical approach. This implant is deployed under hysteroscopic visualization and requires a sequence of rotary and linear operations for its deployment and release. More specifically, this manually operated actuator is a hand held device designed to transmit the required forces in a particular sequence to effect both implant deployment and release at a target location. In order to design the actuator and to investigate its mechanical behavior, a three-dimensional (3D) Computer Aided Design (CAD) model was developed and Finite Element Method (FEM) was used for simulations and optimization. Actuator validation was performed following a number of successful bench-top in-air deployments and in-vitro deployments in animal tissue and explanted human uteri. During these deployments it was observed that the actuator applied the required forces to the implant resulting in successful deployment. Initial results suggest that this actuator can be used single handedly during the deployment phase. The ongoing enhancement of this actuator is moving towards “first-in- man” clinical trials

Computational Treatment of Mixing Process in Stirred Tank

Stirred tanks are widely used in many industrial processes. The quality of mixing process generated by the impellers can be determined using either experimental and simulation methods by using computational fluid dynamics (CFD) or both methods.Numerous models and solution techniques have been developed over the years to help describe a wide variety of fluid motion. In this study computational fluid dynamics were performed to examine the flow characteristics of Mixing processes can be based on a number of mechanisms, from agitation to sparging to static flow manipulation. Agitation in a stirred tank is one of the most common operations, yet presents one of the greatest challenges in the area of computer simulationsix flat blades Rushton turbine type in cases of one impeller only and two impellers in baffled tank., Making an optimization design for mixing tank. The Multiple Reference Frame (MRF) approach was used to simulate the impeller rotation. ANSYS Fluent 15.07 solver and the RNG turbulence model Were used

Fluid-structure Interaction and Multidisciplinary Design Analysis Optimization of Composite Wind Turbine Blade

A multidisciplinary design analysis optimization (MDAO) process is defined for a composite wind turbine blade to optimize its aerodynamic and structural performance by developing a fluid-structural interaction (FSI) system. The objectives are to maximize aerodynamic efficiency and structural robustness while reducing blade mass and total cost. In the previous research, a MDO process of a composite wind turbine blade has been pioneered as an effective process to develop structurally optimized blade design. Present MDAO process is defined in conjunction with structural and aerodynamic performance of the blade which is divided into three steps and the design variables considered are related to the shape parameters, twist distributions, pitch angle, material and the relative thickness based on number of composite layers at different blade sections. Maximum allowable tip deformations, modal frequencies and allowable stresses are set as design constraints. The results of the first step are aerodynamically optimal angle of attack of airfoils for the blade cross-sections along the blade span wise direction, and the uniform pressure distribution along the blade at maximum lift and wind conditions. Airfoil performance is predicted with 2D airfoils analysis, while 3D CFD analysis is performed by ANSYS CFX software. The second step yields optimal material, composite layup distribution of the blade and involves fluid structure interaction system hence actual pressure loads on the blade can be used for the structural analysis. A parameterized finite element model of the blade created in ANSYS ACP composite prepost and used to define the composite layups of the blade. At the last step, the results of the CFD and the structural analysis are used for the optimization process accompanied by the cost estimation to obtain a compromised solution between aerodynamic performance and structural robustness. For the MDAO process number of design of experiments (DOEs) is defined by G-optimality method and a response surface is created. Additionally, by consideration of maximum power output, minimum weight and cost as prior objectives, an optimal blade design is found within the pre-defined design variable parameters and structural constraints. Sensitivity analysis is performed to observe the impact of input parameter on each output parameters for enhanced control of the MDAO process. Further, to improve aerodynamic performance of the blade, new design approach with modified Tip (winglet) and rotor section is studied and substantial improvement in power generated over high quality baseline wind turbine blade is presented