Sheet Metal Design Considerations

The International Journal of Advanced Manufacturing Technology, 2011

Geometrical optimization of structural components is a topic of high interest for engineers involved with design activities mainly related to mass reduction. The study described in these pages focuses on the optimization of plates subjected to bending for which stiffness is obtained by a pattern of ribs. Although stiffening by means of ribs is a well-known and old technique, the design of ribs for maximum stiffness is often based on practice and experience. Classical optimization methods such as topological, topographical and parametric optimization fail to give an efficient design with a reasonable programming effort, especially when dealing with many and complex constraints. These constraints are both technical and technological. A most promising technique to obtain optimal rib patterns was to define a set of feasible rib trajectories and then to select the subset with the most efficient combinations. The result is not unique and a method to select the optimal patterns is required. In fact, the stiffening effect increases with increasing rib length, but at a greater cost. A trade-off must be found between structural performance and cost: The tools to guide this selection process is the main objective of the paper, with particular attention in evaluating the stiffening due to the presence of beads on the plate with a close link with the production system and possible technological constraints which can occur during manufacturing processes, such as minimum rib distance or the presence of discontinuities or the presence of holes or other elements on the plate. A special tool with enforced rib cross section is considered, and optimal rib deployment has to be found. Numerical examples attached show the methodology and obtainable results.

Load carrying brackets in the engine room of Scania's busses are almost exclusively manufactured through bending of sheet metal. It is believed that pressing, rather than bending, could result in lighter components. Lighter components mean less weight for the bus to transport and could, for example, result in allowing additional passengers on the bus.

Journal of Materials Processing Technology, 2006

In the present paper optimization has been used to evaluate alternative sheet metal forming processes. Six process setups were first defined in a hierarchy of designs and optimization was then used to evaluate each forming process of these designs. The challenge in designing the forming process was to avoid failure in the material and at the same time reach an acceptable through thickness strain. The conclusions of this study is that there may exist a different process that can give an improved product for the desired geometry. This process might be impossible for the optimization algorithm to reach due to either a poor starting point or a not so wise process setup .

Material selection in architecture is not only about choosing the strongest, cheapest, or most obvious materials available. Architects also choose warm, formal, functional, or local materials for buildings. And the material options are not limited by only these considerations. The material selection process is a complex process that is influenced and determined by numerous preconditions, decisions and considerations. The current material selection tools, however, focus mainly on the technical aspects of materials. In order to make well-considered and justifiable material choices, architects have a need for information on the whole spectrum of aspects considered during the design and selection process. Earlier work presented a framework, based on a literature study and the analysis of in-depth interviews, in which the different attributes of materials that contribute to a design project were identified and organized. To refine this framework and make it available for architects durin...

2004

This section describes the loads that shall be taken into consideration in designing the FIRE device. The design loads shall be established in accordance with the definitions given below and combined in the manner prescribed in Section I-2.0. I-1.1 Dead Load (D) Dead loads are essentially constant during the life of the structure and normally consist of the weight of the components considered. The dead load for a coil includes the weight of the winding, casing, insulation, and attached support structures. For the vacuum vessel system, the dead load includes the weight of the vessel, first wall, divertors, ports and their attachments, cooling/heating systems including coolant, and insulation. I-1.2 Design Pressure (P) [Ref. 3 (Section III, NCA-2142.1(a) & NB-3112.1)] Internal and external design pressures are loads caused by liquids and gases distributed over the surface of a component. For example, in the case of cryogenic coolant passages, the design pressure is that imposed by the cryogenic supply system in a worst-case fault scenario. And for the vacuum vessel, the design pressure shall include vacuum pressure and pressure due to the heating and cooling system. I-1.3 Normal Operating Thermal Effects (To) [Ref. 3 (Section III, NB-3213.13)] The effects of all temperature changes and temperature differences within and between components shall be accounted for in the design. The temperature changes during normal operation range from the lowest temperature of the coolant to a maximum due to resistive dissipation of electric currents, nuclear heating, bakeout, and radiation.

Sheet metal parts are widespread used in the assembly of product such as automotive and airframes bodies. This paper presents how Dimensional Engineering (DE) process and the simulation-based tolerance analysis used in the development process of the assembly tolerance analysis. Focusing on the sheet metal component, which should be treated as non-rigid part, compliant assembly analyzing is adopted in the simulation process. Deviations of the components due to the tolerance between pin locator and hole and the locator layout scheme are defined as the key point characteristics (KPCs) during the optimization process. Inspection data incorporated close-loop optimizing approaches is applied to the final deviation estimation in simulation. Dimensional engineering software solution, 3DCS, is used as the analyzing tool in the case study

2013 IEEE International Symposium on Assembly and Manufacturing (ISAM), 2013

Product Data Management (PDM) systems were created in the early of 1980s. The development has increased rapidly in these, and also in different CADsystems. However, there still occur problems in linking these two systems together and getting the full benefit out from the PDM system. Modern PDM systems, together with CAD softwares, do not take into account the different design aspects when designing for example sheet metal products. CAD softwares give automatically some parameters for sheet metals but these parameters may not be correct ones. In almost every PDM system there is a possibility for giving almost realtime feedback between the designers and manufacturers, but this feature is rarely used. Only few system users actually know what kind of help the PDM is offering and what kind of add-ons can be added into the system. The main problem seems to be that there is not just one way to design a sheet metal product and transform it to the PDM, even if all the users were using the same PDM system with the same given introduction.

2016

With the advent of high-speed computers more and more theoretical research in manufacturing area is transferred to technology that enable complex CAD modeling and solution of the nonlinear, large deformation finite element problems. All OEMs require their suppliers to use the simulation tools before prototypes are made on the shop-floor. Virtual simulations help produce an array of acceptable designs some of which give information on identifying and setting the optimum values of the forming process parameters. This paper discusses the application of rotatable orthogonal array (OA) and 5-axes response surface methodology (RSM) to identify the optimum values related to metal forming of an example part with thickness as the response.

Scientia

Pathologies by humidity in the materials for construction RESUMEN La microestuctura del material bajo condiciones críticas de humedad genera que el vapor de agua presente migre a través del elemento constructivo, describiendo un gradiente térmico, condensándose en algún punto de esa trayectoria al encontrar un plano frío. Esta humedad sumada a otros factores como la luz, el oxigeno, el pH, los nutrientes y la contaminación atmosférica origina el biodeterioro provocando la aparición de microsistemas y generando lesiones en el material mecánicas y Químico Biológicas. Estas patologías implican restauración o cambio. Sin ser excluyentes desde una mirada del Diseño se debe considerar como factor de deterioro el psicodeterioro del material.