/pdf/alfred-weber-s-theory-of-the-location-of-industries-54x5xzdke4.pdf

Alfred Weber's Theory of the Location of Industries@@@Coastwise Cruising, from Erith to Lowestoft

Additive manufacturing (AM) is a new paradigm for the design and production of high-performance components for aerospace, medical, energy, and automotive applications. This review will exclusively cover directed energy deposition (DED)-AM, with a focus on the deposition of powder-feed based metal and alloy systems. This paper provides a comprehensive review on the classification of DED systems, process variables, process physics, modelling efforts, common defects, mechanical properties of DED parts, and quality control methods. To provide a practical framework to print different materials using DED, a process map using the linear heat input and powder feed rate as variables is constructed. Based on the process map, three different areas that are not optimized for DED are identified. These areas correspond to the formation of a lack of fusion, keyholing, and mixed mode porosity in the printed parts. In the final part of the paper, emerging applications of DED from repairing damaged parts to bulk combinatorial alloys design are discussed. This paper concludes with recommendations for future research in order to transform the technology from “form” to “function,” which can provide significant potential benefits to different industries.

https://www.mdpi.com/2079-6412/9/7/418/pdf

State of the Art in Directed Energy Deposition: From Additive Manufacturing to Materials Design

An improved ant colony algorithm is proposed for robot path planning under a static environment.Grid method is used to establish workspace model of the robot.Furthermore,the strategy of backspace from traps and the meeting strategy were applied to path planning of mobile robot,so it avoided path-locked situation as well as improved the efficiency of planning optimal path.The simulation results show that the performance of path planning can be obviously improved by the proposed ant colony algorithm,and the algorithm is very simple and efficient.

An ImproVed Ant Colony Algorithm for Robot Path Planning

Part I: Using CAD/CAM Systems 1 Introduction 2 3D Modeling and Viewing 3 Modeling Aids and Tools 4 Engineering Drawings 5 CAD/CAM Programming Part II: Geometric Modeling 6 Curves 7 Surfaces 8 NURBS 9 Solids 10 Features Part III: Computer Graphics 11 Graphics Display 12 Transformations 13 Visualization 14 Computer Animation Part IV: Product Design and Development 15 Mass Properties 16 Assembly Modeling 17 Finite Element Method 18 Product Data Exchange 19 Collaborative Design Part V: Product Manufacturing and Management 20 Engineering Tolerances 21 Process Planning 22 Part Programming 23 Product Lifecycle Management Appendix A Bibliography Appendix B Linear Algebra Appendix C ANSI and ISO Tolerance Tables

Mastering CAD/CAM

The research on the use of virtual reality (VR) in the design domain has been conducted in a fragmentary way so far, and some misalignments have emerged among scholars In particular, the actual support of VR in early design phases and the diffusion of practices involving VR in creative design stages are argued In the present paper, we reviewed VR applications in design and categorized each of the collected 86 sources into multiple classes These range from supported design functions to employed VR technologies and the use of systems complementing VR The identified design functions include not only design activities traditionally supported by VR, such as 3D modelling, virtual prototyping, and product evaluation, but also co-design and design education beyond the early design phases The possibility to support early design phases by means of VR is mirrored by the attention on products that involve an emotional dimension beyond functional aspects, which are particularly focused on in virtual assemblies and prototypes Relevant matches between VR technologies and specific design functions have been individuated, although a clear separation between VR devices and supported design tasks cannot be claimed

Applications of Virtual Reality in Engineering and Product Design: Why, What, How, When and Where

Maier and Fadel pioneered Affordance-Based Design (ABD) based on Gibson?s revolutionary theory of affordances and Norman?s deployment of the concept in his book, ?The Design of Everyday Things?. Gibson (1979) introduced the affordance concept into the discipline of Ecological Psychology to address the interactions between an object and an agent. The Ecological approach includes the direct perception of affordances for the user along with a consideration of the users? biomechanics. However, as the concept of affordance was imported and utilized in different disciplines, including engineering design, some important aspects of Ecological theory were omitted.

This paper is an attempt to review the definitions and different utilizations of the affordance concept focusing on the design of usable products to identify the different views and the missing elements. After addressing the divergent viewpoints of affordances, we provide recommendations to improve the usability aspects in ABD by considering direct perception and ergonomics. We claim that a design (based on affordances) that fails to address both criteria may result in a product that is less usable.

/pdf/a-review-of-affordances-and-affordance-based-design-to-4o95qke89a.pdf

A Review of Affordances and Affordance-Based Design to Address Usability


 Routing or path-planning is the problem of finding a collision-free and preferably shortest path in an environment usually scattered with polygonal or polyhedral obstacles. The geometric algorithms oftentimes tackle the problem by modeling the environment as a collision-free graph. Search algorithms such as Dijkstra’s can then be applied to find an optimal path on the created graph. Previously developed methods to construct the collision-free graph, without loss of generality, explore the entire workspace of the problem. For the single-source single-destination planning problems, this results in generating some unnecessary information that has little value and could increase the time complexity of the algorithm. In this paper, first a comprehensive review of the previous studies on the path-planning subject is presented. Next, an approach to address the planar problem based on the notion of convex hulls is introduced and its efficiency is tested on sample planar problems. The proposed algorithm focuses only on a portion of the workspace interacting with the straight line connecting the start and goal points. Hence, we are able to reduce the size of the roadmap while generating the exact globally optimal solution. Considering the worst case that all the obstacles in a planar workspace are intersecting, the algorithm yields a time complexity of O(n log(n/f)), with n being the total number of vertices and f being the number of obstacles. The computational complexity of the algorithm outperforms the previous attempts in reducing the size of the graph yet generates the exact solution.

Planning the Shortest Path in Cluttered Environments: A Review and a Planar Convex Hull-Based Approach

During the past few years, metal based additive manufacturing technologies have evolved and may enable the direct fabrication of heterogeneous objects with full spatial material variations. A heterogeneous object has potentially many advantages and in many cases can realize appearance and/or functionality that homogeneous objects cannot achieve. In this work we employ a preprocess computing combined with a multi-objective optimization algorithm based on the modeling of the LENS deposition of multiple materials to optimize the fabrication process. The optimization methodology is applied to the fabrication of cermet composite (using Inconel 718 and ceramic powders) with prescribed material feeding rates. The multi-objective optimization considers that the energy consumption and the material waste during the fabrication process should be minimized, while the probability of the melting of the powders should be maximized. The optimization software modeFRONTIER® is used to drive the computation procedure with a MATLAB code. The results show the design and objective spaces of the Pareto optimal solutions, and enable the users to select preferred setting configurations from the set of optimal solutions.Copyright © 2015 by ASME

Optimization of Process Parameters in Laser Engineered Net Shaping (LENS) Deposition of Multi-Materials

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;In this paper, we review the literature related to the reuse of computer-based simulation models in the context of systems design.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;Models are used to capture aspects of existing or envisioned systems and are simulated to predict the behavior of these systems. However, developing such models from scratch requires significant time and effort. Researchers have recognized that the time and effort can be reduced if existing models or model components are reused, leading to the study of model reusability. In this paper, we review the tasks necessary to retrieve and reuse model components from repositories, and to prepare new models and model components such that they are more amenable for future reuse.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;Model reuse can be significantly enhanced by carefully characterizing the model, and capturing its meaning and intent so that potential users can determine whether the model meets their needs. Traditionally, the meaning and intent of models has been captured in textual documentation, but more recently, semantically rich, axiomatized approaches using model characteristics based on ontologies have been introduced that enable algorithmic support for the identification, discovery, and reuse of models. Researchers have also recognized that the opportunity for reuse significantly increases when models are modularized into composable model components. While many repositories and frameworks for modular modeling have been recently developed, it is important to recognize that without considerable forethought in terms of model architecture, model composability often remains elusive.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;Even when models are well-characterized and organized in a repository, model users need to perform several tasks before they can successfully reuse these models and components for a specific analysis scenario. These tasks include searching, optionally adapting, composing, integrating and validating models and model components. We will review the literature on each of these tasks and focus on identifying opportunities for further improvement of model reuse support frameworks.&lt;/div&gt;&lt;/div&gt; 

Approaches for Simulation Model Reuse in Systems Design — A Review


 Parametric Optimization is used to solve problems that have certain design variables as implicit functions of some independent input parameters. The optimal solutions and optimal objective function values are provided as functions of the input parameters for the entire parameter space of interest. Since exact solutions are available merely for parametric optimization problems that are linear or convex-quadratic, general non-convex non-linear problems require approximations.
 In the present work, we apply three parametric optimization algorithms to solve a case study of a benchmark structural design problem. The algorithms first approximate the nonlinear constraint(s) and then solve the optimization problem. The accuracy of their results and their computational performance are then compared to identify a suitable algorithm for structural design applications. Using the identified method, sizing optimization of a truss structure for varying load conditions such as a varying load direction is considered and solved as a parametric optimization problem to evaluate the performance of the identified algorithm. The results are also compared with non-parametric optimization to assess the accuracy of the solution and computational performance of the two methods.

Nafiseh Masoudi

Papers

A Review of Affordances and Affordance-Based Design to Address Usability

Planning the Shortest Path in Cluttered Environments: A Review and a Planar Convex Hull-Based Approach

Optimization of Process Parameters in Laser Engineered Net Shaping (LENS) Deposition of Multi-Materials

Approaches for Simulation Model Reuse in Systems Design — A Review

Parametric Optimization for Structural Design Problems