Solid Mechanics Based Design and Optimization for Support Structure Generation in Stereolithography Based Additive Manufacturing

2015 ◽  
Author(s):  
Guanglei Zhao ◽  
Chi Zhou ◽  
Sonjoy Das
Keyword(s):  
Additive Manufacturing ◽  
Solid Mechanics ◽  
Search Algorithm ◽  
Pso Algorithm ◽  
Optimization Method ◽  
Optimized Design ◽  
Support Structures ◽  
Support Structure ◽  
Element Analysis ◽  
Structure Generation

Support structures are typically required to hold parts in place in various additive manufacturing processes. Design of support structure includes identifying both anchor locations and geometries. Extensive work has been done to optimize the anchor locations to reliably keep part in position, and minimize the contacting area as well as the total volume of the support structures. However, relatively few studies have been focused on the mechanical property analysis of the structure. In this paper, we proposed a novel design optimization method to identify the anchor geometry based on solid mechanics theory. Finite element analysis method is utilized to study the stress distribution on both the support structure and main part. Particle Swarm Optimization (PSO) algorithm with a novel constraining handling strategy is employed to optimize the design model. A gradient descent local search algorithm is utilized to quickly locate the global solution in the vicinity explored by PSO. The developed optimization framework is deployed on a bottom-up projection based Stereolithography process. The experimental results show that the optimized design can efficiently reduce the material used on support structure and marks left on the part.

scholarly journals Bio-inspired generative design for support structure generation and optimization in Additive Manufacturing (AM)

CIRP Annals ◽  
2020 ◽  
Vol 69 (1) ◽  
pp. 117-120 ◽  
Author(s):  
Yicha Zhang ◽  
Zhiping Wang ◽  
Yancheng Zhang ◽  
Samuel Gomes ◽  
Alain Bernard
Keyword(s):  
Additive Manufacturing ◽  
Generative Design ◽  
Support Structure ◽  
Structure Generation ◽  
Support Structure Generation

scholarly journals Weight Minimization of Helical Compression Spring Using Gravitational Search Algorithm (GSA)

2015 ◽  
Vol 773-774 ◽  
pp. 277-281 ◽  
Author(s):  
Noor Hafizah Amer ◽  
Nurhidayati Ahmad ◽  
Amar Faiz Zainal Abidin
Keyword(s):  
Search Algorithm ◽  
Gravitational Search Algorithm ◽  
Pso Algorithm ◽  
Optimization Method ◽  
Standard Case ◽  
Weight Minimization ◽  
Compression Spring ◽  
Parametric Studies ◽  
Gravitational Search ◽  
Better Than

Compression spring is one of the most common mechanical componet being used in most mechanisms. Many criteria and constraints should be considered in designing and specifying the spring dimensions. Therefore, it has been one of the standard case studies considered to test a new optimisation algorithm. This paper introduced an optimization method named Gravitational search Algorithm (GSA) to solve the problem of weight minimization of spring. From previous studies, weight minimization of a spring has been investigated by many researcher using various optimization algorithm technique. The result of this study were compared to one of the previous studies using Particle Swarm Optimization (PSO) algorithm. Also, parametric studies were conducted to select the best values of GSA parameters, beta and epsilon. From the results obtained, it was observed that the optimum dimensions and weight obtained by GSA are better than the values obtained by PSO. The best values of beta and epsilon was found to be 0.6 and 0.01 respectively.

Innovative Turbine Stator Well Design Using a Kriging-Assisted Optimization Method

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Julien Pohl ◽  
Harvey M. Thompson ◽  
Ralf C. Schlaps ◽  
Shahrokh Shahpar ◽  
Vincenzo Fico ◽  
...  
Keyword(s):  
Engine Performance ◽  
Internal Flow ◽  
Optimization Method ◽  
Optimized Design ◽  
Element Analysis ◽  
Baseline Design ◽  
Turbine Stator ◽  
Air Temperatures ◽  
Design Variables ◽  
Deflector Plate

At present, it is a common practice to expose engine components to main annulus air temperatures exceeding the thermal material limit in order to increase the overall engine performance and to minimize the engine specific fuel consumption. To prevent overheating of the materials and thus the reduction of component life, an internal flow system is required to cool and protect the critical engine parts. Previous studies have shown that the insertion of a deflector plate in turbine cavities leads to a more effective use of reduced cooling air, since the coolant is fed more effectively into the disk boundary layer. This paper describes a flexible design parameterization of an engine representative turbine stator well geometry with stationary deflector plate and its implementation within an automated design optimization process using automatic meshing and steady-state computational fluid dynamics (CFD). Special attention and effort is turned to the flexibility of the parameterization method in order to reduce the number of design variables to a minimum on the one hand, but increasing the design space flexibility and generality on the other. Finally, the optimized design is evaluated using a previously validated conjugate heat transfer method (by coupling a finite element analysis (FEA) to CFD) and compared against both the nonoptimized deflector design and a reference baseline design without a deflector plate.

Efficient Process Planning Strategies for Additive Manufacturing

2017 ◽  
Author(s):  
Uppili Srinivasan Venkatesan ◽  
S. S. Pande
Keyword(s):  
Additive Manufacturing ◽  
Process Planning ◽  
Fitness Function ◽  
Performance Measure ◽  
Performance Parameters ◽  
Support Structures ◽  
Structure Generation ◽  
Part Quality ◽  
Material Utilization ◽  
Am Processes

This work reports the development of robust and efficient algorithms for optimum process planning of Additive Manufacturing (AM) processes needing support structures during fabrication. In particular, it addresses issues like part hollowing, support structure generation and optimum part orientation. Input to the system is a CAD model in STL format which is voxelized and hollowed using the 2D Hollowing strategy. A novel approach to design external as well as internal support structures for the hollowed model is developed considering the wall thickness and material properties. Optimum orientation of the hollowed part model is computed using Genetic Algorithm (GA). The Fitness Function for optimization is the weighted average of process performance parameters like build time, part quality and material utilization. A new performance measure has been proposed to choose the weightages for performance parameters to obtain overall optimum performance. The paper presents, in detail, the design and development of algorithms with results for typical case studies. The proposed methodology will significantly contribute to improving part quality, productivity and material utilization for AM processes.

Analysis of 24Slot wound field salient rotor switched-flux machine based on 2D-FEA

2016 ◽  
Vol 13 (5) ◽  
pp. 381-385 ◽  
Author(s):  
Faisal Khan ◽  
Erwan Sulaiman ◽  
Hassan Ali Soomro ◽  
Fairoz Omar ◽  
Zarafi Ahmad
Keyword(s):  
High Speed ◽  
Design Methodology ◽  
Optimization Method ◽  
Optimized Design ◽  
Flux Linkage ◽  
Element Analysis ◽  
Content Type ◽  
Three Phase ◽  
Rotor Poles ◽  
Dimensional Finite Element

Purpose The paper aims to propose and compare two new structures of a three-phase wound field salient rotor (WFSR) switched-flux motor (SFM) with 24 stator slots and 10 or 14 rotor poles, respectively, for high-speed operation. Design/methodology/approach The paper outlines the motor general construction and design concept of proposed machines. Flux linkage, average torque, rotor mechanical strength and torque–speed characteristics of both machines were analyzed and compared by two-dimensional finite element analysis (2D-FEA). Deterministic optimization method was adopted to enhance the characteristics of 24Slot-10Pole WFSR SFM. Findings The paper provides simulation results and discusses how 24Slot-10Pole WFSR SFM structure is superior to the 24Slot-14Pole in the aspects of flux linkage, average torque and power. It further concludes that the optimized design of 24Slot-10P has achieved 58 and 72 per cent higher average torque and power compared to initial design, as well as high average torque and power compared to 24Slot-14P design. Originality value Optimized structure of the 24Slot-10Pole WFSR SFM with non-overlapping windings has been proposed.

Investigation of support structure parameters and their affects during additive manufacturing of Ti6Al4V alloy via electron beam melting

2020 ◽  
pp. 146442072098166
Author(s):  
Wadea Ameen ◽  
Muneer Khan Mohammed ◽  
Abdulrahman Al-Ahmari ◽  
Naveed Ahmed ◽  
Syed Hammad Mian
Keyword(s):  
Electron Beam ◽  
Additive Manufacturing ◽  
Process Parameters ◽  
Electron Beam Melting ◽  
High Energy ◽  
Ti6al4v Alloy ◽  
High Energy Density ◽  
Support Structures ◽  
Support Structure ◽  
Support Design

Electron beam melting technology offers various benefits like the reduced product cycle time, customization, flexibility, high energy density and less material wastage. However, electron beam melting still suffers from redundant usage of support structure material while fabricating overhang structures. The support structures not only consume additional material, but also require additional time for their design and removal. The optimized support structures have to be designed in such a way that they consume minimum material, are easy to remove and are free from defects. The aim of the current study is to study the effect of support design and process parameters on the performance of the support structures (cost and quality) during additive manufacturing of Ti6Al4V alloy via electron beam melting. The results show that the support structures parameters play a significant role in the cost of the applied support and the accuracy of the fabricated object. It was found that with appropriate selection of support design and process parameters, it is possible to reduce the support volume and hence the fabrication cost in metal additive manufacturing (AM). A tooth height of 3 mm, no support offset of 2 mm, and fragmentation separation width of 0.8 mm resulted in lower support volumes without having any effect on the quality of the overhang. This study systematically investigated the support structure design and their outcomes on overhang fabrication. Its conclusions could add value to the researchers working on additive manufacturing of Ti6Al4V alloy by electron beam melting.

scholarly journals A Multiobjective Optimal Operation of a Stand-Alone Microgrid Using SAPSO Algorithm

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Guoping Zhang ◽  
Weijun Wang ◽  
Jie Du ◽  
Hua Liu
Keyword(s):  
Optimization Model ◽  
Optimization Problem ◽  
Search Algorithm ◽  
Pso Algorithm ◽  
Optimization Method ◽  
Optimal Operation ◽  
Renewable Energy Resources ◽  
Diesel Generator ◽  
Pareto Solution ◽  
Operation Optimization

Microgrid is an effective way to utilize renewable energy resources, especially for satisfying the electricity requirements in remote islands. The operation optimization of an island microgrid is critical to ensure the effective performance of the whole microgrid system, and it is usually a multiconstrained and multiobjective optimization problem. The main contribution of this study is an operation optimization method for the stand-alone microgrid system in a remote island, which includes wind, PV, battery, and diesel generator. In this paper, a novel operation optimization model for stand-alone microgrid is proposed, in which the battery system is considered separately; the multiobjective day-ahead optimization model considering economic cost, battery depreciation cost, and environmental protection cost is established. In the optimization, the output power of diesel generator and energy storage system are chosen as the decision variables. For this purpose, an efficient search algorithm combining the particle swarm optimization (PSO) algorithm and the simulated annealing (SA) algorithm is developed. The hybrid algorithm is applied to search for the Pareto solution set of the optimization problem. The search results are compared with those from traditional PSO algorithm. Also, a grey target decision-making theory based on the entropy weight method is proposed to identify the best trade-off scheduling scheme among all the solutions, and the results are compared with those from two other commonly used subjective and objective methods. The results show that the proposed optimization method can be applied to the day-ahead operation optimization of the microgrid system and help the user obtain the best compromise operation scheme for stand-alone microgrid.

scholarly journals Aerodynamic Design Optimization of a Morphing Leading Edge and Trailing Edge Airfoil–Application on the UAS-S45

2021 ◽  
Vol 11 (4) ◽  
pp. 1664
Author(s):  
Musavir Bashir ◽  
Simon Longtin-Martel ◽  
Ruxandra Mihaela Botez ◽  
Tony Wong
Keyword(s):  
Search Algorithm ◽  
Optimization Technique ◽  
Leading Edge ◽  
Endurance Performance ◽  
Pso Algorithm ◽  
Optimization Method ◽  
Pattern Search ◽  
Aerodynamic Optimization ◽  
Trailing Edge ◽  
Sst Turbulence Model

This work presents an aerodynamic optimization method for a Droop Nose Leading Edge (DNLE) and Morphing Trailing Edge (MTE) of a UAS-S45 root airfoil by using Bezier-PARSEC parameterization. The method is performed using a hybrid optimization technique based on a Particle Swarm Optimization (PSO) algorithm combined with a Pattern Search algorithm. This is needed to provide an efficient exploitation of the potential configurations obtained by the PSO algorithm. The drag minimization and the endurance maximization were investigated for these configurations individually as two single-objective optimization functions. The aerodynamic calculations in the optimization framework were performed using the XFOIL solver with flow transition estimation criteria, and these results were next validated with a Computational Fluid Dynamics solver using the Transition γ−Reθ Shear Stress Transport (SST) turbulence model. The optimization was conducted at different flight conditions. Both the DNLE and MTE optimized airfoils showed a significant improvement in the overall aerodynamic performance, and MTE airfoils increased the efficiency of CL3/2/CD by 10.25%, indicating better endurance performance. Therefore, both DNLE and MTE configurations show promising results in enhancing the aerodynamic efficiency of the UAS-S45 airfoil.

Torque ripples reduction in a synchronous reluctance motor by rotor parameters optimization

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammad Reza Naeimi ◽  
Karim Abbaszadeh ◽  
Reza Nasiri-Zarandi
Keyword(s):  
Finite Element ◽  
Pso Algorithm ◽  
Torque Ripple ◽  
Parameters Optimization ◽  
Optimized Design ◽  
Element Analysis ◽  
Content Type ◽  
Synchronous Reluctance Motor ◽  
Reluctance Motor ◽  
Optimization Parameters

Purpose High torque ripple is the significant challenge of the synchronous reluctance machine in household electric appliances, electric vehicles and so on. This paper aims to present an optimized design of a synchronous reluctance rotor structure to reduce the torque ripple with improving the average torque by the particle swarm optimization (PSO) algorithm. Design/methodology/approach The optimization of rotor geometries has been investigated. Most of the rotor parameters such as the width of iron parts, the width of barriers along d and q axes and the endpoint angle of barriers are optimized by a new method using the PSO algorithm. After optimization, the resulted optimum design along with the initial design is simulated by two-dimensional finite element method and results are compared. At the end, a prototype is constructed and tested. Results of the experiment are compared with the simulation results where acceptable adoption is yielded. Findings Minimizing the torque ripple without losing the average torque is an important achievement of the synchronous reluctance motor (SynRM) optimization; furthermore, the finite element analysis and experimental results indicate that the torque ripple of the SynRM with the optimized rotor is reduced significantly. Also, increasing the number of optimization parameters can effectively obtain an accurate shape of the SynRM barrier. Originality/value Because of the high number of parameters in synchronous reluctance rotors, the majority of proposed optimizations did not use all geometric parameters of the rotor and tried to simplify the optimization by ignoring several optimization parameters or reducing the number of flux barriers. In this optimization, most of the rotor parameters have been used to achieve the precise barrier shape with the aim of reducing the torque ripple in SynRM.

Sign in / Sign up

Export Citation Format

Share Document