Management of the engineering data for manufacturing

Most companies have adopted the use of computer integrated engineering software to cope with the increasing competition and pressure to produce better quality and at a faster rate, enhancing their systems on this basis. Models are designed on computers, designs are validated in the software and tool paths for manufacturing are generated in different specific software. All engineering information is generated and stored in computers. This development enhances faster rate of works in companies; however, some problems such as the management of the data arise. All departments in a business work separately, but for the same purpose. It is required for each department to have access to related information. The existence of a system in which the information is checked and managed depending on their creation time, versions and the department is of importance. In this article, a system that allows not only the mechanical design department but also the manufacturing, storage, process planning, quality control, electrical design, purchasing departments, etc. to have access to the required information has been developed. In the absence of this kind of system, loss of time, scraps and loss of engineering time would be investigated. After starting up the system, its benefits are defined. Tracing the workflows for management purposes would be handled by the system. A 'Validation of Design' process is modelled for the company. The information can be accessible to only those responsible for the data, and not anyone else. This allows users to work in a better environment, hence, increases productivity.

Generation of Continuous Toolpaths for Additive Manufacturing Using Implicit Slicing

The generation of footpaths for additive manufacturing (AM), a process commonly known as “slicing,” has a strong impact on the performance of both the associated hardware systems and the resulting objects. Available slicers invariably produce discontinuous tootpaths, featuring jumps or so-catted “travel moves” during which the deposition of material or/and energy must be hatted. For AM processes using slowly solidifying feedstock materials, such as thermosetting polymers or cementitious mixtures such as concrete, these tootpath discontinuities are highly undesirable due to the artifacts they generate. This renders existing sticers difficult to use in such applications, and presents a road-block to the adoption of AM for such material systems. In the present work, this difficulty is addressed by the development of a simple geometric criterion for the existence of continuous tool-paths that are capable of producing a specified input geometry. This development is based on the principles of morphological geometric analysis and graph theory. It is shown that, for any geometric feature with a characteristic thickness at least twice the extrusion width, a continuous toolpath exists. Furthermore, a general-purpose algorithm for continuous toolpath generation, for arbitrarily shaped objects satisfying this criterion, is developed and demonstrated on a representative test problem. Finally, conclusions and the path forward for the usage of this approach with existing AM systems is explored.

Modelling and Simulation of Mechanical Loads and Residual Stresses in Deep Rolling at Elevated Temperature

Based on the concept of Process Signatures, the deep rolling process is analyzed, aiming at functional relationships between material modifications and internal material loads during the process. The focus of this work is to investigate the influence of the workpiece temperature on the generated residual stress components. For this purpose, extensive finite element simulations of deep rolling were conducted, taking into account the effect of neighboring tool paths on the internal material loads and residual stress. A kinematic strain hardening model was parameterized and utilized and the simulations were validated experimentally. Simulated residual stresses agree qualitatively well with measurements and show a strong influence of the workpiece temperature as expected. Process Signature Components were generated, taking into account the maximal and minimal residual stress as well as their respective positions beneath the workpiece surface.

Generation Method of Cutting Tool Paths for High-Speed and High-Quality Machining of Free-Form Surfaces

In general, NC programs for machining free-form surfaces using a computer numerical control (CNC) machine tool are generated using a computer-aided manufacturing (CAM) system. The tool paths (CL data) generated by a CAM system are approximated straight-line segments based on tolerance (allowable error). As a result, the tolerance affects the machining accuracy and time. If the tolerance is set to a small value, the lengths of the segments are shortened, and the machining accuracy is improved. The process in which a CNC machine tool reads and analyzes an NC program and controls the motors requires a minimum processing time of an NC program block (block-processing time). Therefore, if the lengths of the approximated straight-line segments are too small, it will be impossible to reach the indicated feed speed, and the machining time will be longer. In this study, by identifying the block-processing time of a CNC controller and deriving the appropriate length of the approximated straight-line segment based on the block-processing time, a CL data creation method that is capable of high-speed and high-accuracy free-form surface machining is proposed. In addition, experimental verification tests of the method are conducted.

Modeling and simulation of reconfigurable systems with applications to the polishing process

This thesis presents a newly developed system for simulation and control of reconfigurable machines and applications in the polishing process. A software package is developed that consists of the Varying Topology Simulation and Control System (VT-Sim) as well as the Polishing CAM (P-CAM) software system. VT-Sim can simulate and control reconfigurable machines of serial or tree structures. It is developed based on mechatronic modules, each of which has a graphic user interface that can be connected to a physical module. The selected modules are linked through a graph-based topology design platform to generate an assembled system together with the equations for simulation and control. P-CAM can simulate and generate CNC codes for the polishing process. The roughness of the polished parts is simulated for selected polishing parameters. Once satisfied, polishing tool paths can be generated and visualized.

Modeling and simulation of reconfigurable systems with applications to the polishing process

This thesis presents a newly developed system for simulation and control of reconfigurable machines and applications in the polishing process. A software package is developed that consists of the Varying Topology Simulation and Control System (VT-Sim) as well as the Polishing CAM (P-CAM) software system. VT-Sim can simulate and control reconfigurable machines of serial or tree structures. It is developed based on mechatronic modules, each of which has a graphic user interface that can be connected to a physical module. The selected modules are linked through a graph-based topology design platform to generate an assembled system together with the equations for simulation and control. P-CAM can simulate and generate CNC codes for the polishing process. The roughness of the polished parts is simulated for selected polishing parameters. Once satisfied, polishing tool paths can be generated and visualized.

Design and Analysis of Hybrid Fused Filament Fabrication Apparatus for Fabrication of Composites

Background: Additive manufacturing is the most famous technology which requires materials or composites to be fabricated with layer by layer deposition strategy. Due to its lower cost, higher accuracy and less material wastage; this technology is used in almost every sector. But in many applications there is a need to alter the properties of a product in a certain direction with the help of some reinforcements. With the use of reinforcements, composite layers can be fabricated using additive manufacturing technique which will enhance the directional properties. A novel apparatus is designed to spray the reinforcement material into the printed structures in a very neat and precise manner. This spray nozzle is fully automated, which works according to tool-paths generated by slicing software. The alternate deposition of layers of reinforcement and build materials helped to fabricate customized composite products. Objective: The objective of present study is to design and analyze the working principle of novel technique which has been developed to fabricate composite materials using additive manufacturing. The apparatus is numerically controlled by computer according to CAD data which facilitates the deposition of alternate layers of reinforcement and matrix material. The major challenges during the design process and function of each component has been explored. Methods: The design process is initiated after comprehensive literature review performed to study previous composite manufacturing processes. The recent patents published by different patent offices of the world are studied in detail and analysis has been used to design a low cost composite fabrication apparatus. A liquid dispensing device comprises a storage tank attached with a pump and microprocessor. The microprocessor receives the signal from the computer as per tool paths generated by slicing software which decides the spray of reinforcements on polymer layers. The spraying apparatus moves in coordination with the primary nozzle of the Fused Filament Fabrication process. Results: The hybridization of Fused Filament Fabrication [process with metal spray process has been successfully performed. The apparatus facilitates the fabrication of low cost composite materials along with flexibility of complete customization of composite manufacturing process. The anisotropic behaviour of products can be easily controlled and managed during fabrication which can be used for different applications.