scholarly journals An Intelligent Aspect of CAD for Mechanical Design : The Conceptual Design of a Simple Object

1986 ◽  
Vol 29 (247) ◽  
pp. 301-305
Author(s):  
Ikuo ITO ◽  
Takao ONOZAWA
Author(s):  
David G. Ullman ◽  
Thomas G. Dietterich ◽  
Larry A. Stauffer

This paper describes the task/episode accumulation model (TEA model) of non-routine mechanical design, which was developed after detailed analysis of the audio and video protocols of five mechanical designers. The model is able to explain the behavior of designers at a much finer level of detail than previous models. The key features of the model are (a) the design is constructed by incrementally refining and patching an initial conceptual design, (b) design alternatives are not considered outside the boundaries of design episodes (which are short stretches of problem solving aimed at specific goals), (c) the design process is controlled locally, primarily at the level of individual episodes. Among the implications of the model are the following: (a) CAD tools should be extended to represent the state of the design at more abstract levels, (b) CAD tools should help the designer manage constraints, and (c) CAD tools should be designed to give cognitive support to the designer.


Author(s):  
Farhad Aghili

The paper presents a new paradigm and conceptual design for reconfigurable robots. Unlike conventional reconfigurable robots, our design doesn't achieve reconfigurability by utilizing modular joints. But the robot is equipped with passive joints, i.e. joints with no actuator or sensor, which permit changing the Denavit-Hartenberg (DV) parameters such as the arm length, and the twist angle. The passive joints are controllable when the robot forms a closed kinematic chain. Also each passive joint is equipped with a built-in brake mechanism which is normally locked but it can be released whenever changing of the parameters is required. Kinematics analysis of such a robot plus control synthesis and mechanical design of the brake mechanism are described.


Author(s):  
Stefan Wo¨lkl ◽  
Kristina Shea

The importance of the concept development phase in product development is contradictory to the level and amount of current computer-based support for it, especially with regards to mechanical design. Paper-based methods for conceptual design offer a far greater level of maturity and familiarity than current computational methods. Engineers usually work with software designed to address only a single stage of the concept design phase, such as requirements management tools. Integration with software covering other stages, e.g. functional modeling, is generally poor. Using the requirements for concept models outlined in the VDI 2221 guideline for systematic product development as a starting point, the authors propose an integrated product model constructed using the Systems Modeling Language (SysML) that moves beyond geometry to integrate all necessary aspects for conceptual design. These include requirements, functions and function structures, working principles and their structures as well as physical effects. In order to explore the applicability of SysML for mechanical design, a case study on the design of a passenger car’s luggage compartment cover is presented. The case study shows that many different SysML diagram types are suitable for formal modeling in mechanical concept design, though they were originally defined for software and control system development. It is then proposed that the creation and use of libraries defining generic as well as more complicated templates raises efficiency in modeling. The use of diagrams and their semantics for conceptual modeling make SysML a strong candidate for integrated product modeling of mechanical as well as mechatronic systems.


Author(s):  
H. V. Darbinyan

Mechanism and function formalization problem is touched in a novel task based conceptual mechanical design method. The general concept and a specific application of this method were reported in earlier publications. Direct dependence between the function and mechanism, identical synthesis tools for various stages of design and for various mechanical objects are the features making the suggested method advantageously different from existing concept design approaches. The core idea of suggested conceptual design method is the direct relation between challenged function and the mechanical entity which is in charge of implementing the requested function. The existing task based conceptual design methods are not satisfying the designer’s needs for scope of application, universality of design means, visualization and formalization of both mechanical and functional fields. Formalization of functions and mechanisms is an important design tool that will facilitate synthesis, analyzes, visualization and archiving (data base creating) processes of mechanical development. Further progress in unveiling the resources of the suggested design method is mostly based on development of formalization means for both categories of functions and mechanisms. The current study is unveiling newly developed function and mechanism description language that is helping to formalize both mechanical and functional categories facilitating their involvement in design process and making the description of a new product’s mechanical development easy and understandable. Function formalization in conjunction with mechanism formalization allows to formulate precisely the design task and concentrate the designer’s attention on solution of a single task strictly arranged in the hierarchical function tree of all involved tasks and functions.


2019 ◽  
Vol 287 ◽  
pp. 01008
Author(s):  
Hrayr Darbinyan

A novel approach of task based conceptual design(TBCD) has been successfully used as direct guider and efficient developer of unique mechanical structures for many cases of mechanical design. Nearly a decade long efforts of elaboration of efficient every day usage formats for this method have been ended in convenient design pages suitable and applicable for revealing, describing, visualizing and managing the data necessary for organizing the design process from task definition to solutions satisfying original design tasks. The aim of current study is to show steps of a solution generation within frames of a single design cycle and extend this action over consecutive design cycles. Those steps are described from standpoint of general concept design method starting from key model and finished with final aggregation matrice as ultimate step of a single design cycle. Unified mathematical expressions are used for introduction and description of all worked out and developed components of conceptual design. The paper is arranged in a way to show gradual steps of conceptual design(CD) of a power transmission system – a pipe wrench life test machine.


Author(s):  
Katsuya Mogami ◽  
Kazuhiro Izui ◽  
Shinji Nishiwaki ◽  
Masataka Yoshimura ◽  
Nozomu Kogiso

Since decision-making at the conceptual design stage critically affects final design solutions at the detailed design stage, conceptual design support techniques are practically mandatory if the most efficient realization of optimal designs is desired. Topology optimization methods using discrete elements such as frame elements enable a useful understanding of the underlying mechanics principles of products, however the possibility of changing prior assumptions concerning utilization environments exists since the detailed design process starts after the completion of conceptual design decision-making. In order to avoid product performance reductions due to such later-stage environmental changes, this paper discusses a reliability-based topology optimization method that can secure specified design goals even in the face of environmental factor uncertainty. This method can optimize mechanical structures with respect to two principal characteristics, namely structural stiffness and eigen-frequency. Several examples are provided to illustrate the utility of the method presented here for mechanical design engineers.


Author(s):  
Szu-Hung Lee ◽  
Pingfei Jiang ◽  
Peter R. N. Childs ◽  
Keith Gilroy

A study on utilising a graphical interface to represent movement transmission within products has been conducted to support a creative conceptual design process that separates the consideration of functional requirements and motion requirements. In engineering design, many representations of product structure have been proposed to assist in understanding how a design is constituted. However, most of these representations demonstrate only functions and are not able to demonstrate design structure. Functional Analysis Diagrams (FAD) provides a solution for this. An FAD shows not only functions but also physical elements by the network of blocks and arrows and thus it is capable of demonstrating various types of information and the design scheme. This characteristic gives FADs an advantage for designers to combine different types of information including useful and harmful interactions to gain an overview of the design task. This study focuses on using circles instead of arrows to represent movement attributes of mechanisms and machine elements in a Kinematic Functional Analysis Diagram (KFAD) and explores methods of utilising it in mechanical design. A commercial case study of medical equipment design conducted with the assistance of KFADs and a component database, mechanism and machine elements taxonomy (MMET), is described to illustrate the process. The design outcome shows that it is feasible to follow the proposed conceptual design process. With the help of KFADs and the machine elements taxonomy to enable consideration of movements, diverse considerations and design solutions are possible.


2011 ◽  
Vol 464 ◽  
pp. 655-659
Author(s):  
Yong Wang ◽  
Guo Niu Zhu ◽  
Zheng Wei Zhu

Structural topology optimization has got a general acceptance in recent years in mechanical design due to its powerful technique for conceptual design. The shortcoming of current development process of mechanical design is discussed and a new approach with structural topology optimization is put forward. The application of the method demonstrates that through innovative utilization of the topology optimization techniques, a multitude of conceptual design proposals based on the design space and design targets can be obtained and then a CAD model with high quality which has a positive impact on the development process is also available.


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