Design And Optimization Under Uncertainty In Sheet Metal Forming Processes Constrained With Failure Analysis

Through the integration of these features, the current research establishes a framework for design under uncertainty in sheet metal forming. The robust design model takes into account producibility requirements through failure analysis and uncertainties from forming conditions and material properties. The approach was demonstrated through a demonstration example of a wheelhouse stamping process used in automobile industry. In addition, model validation approaches taking uncertainty into account are demonstrated in a simulation of a sample flanging process. Overall, this research presents the methodology and feasibility of implementing the framework for design and optimization under uncertainty, which can certainly be generalized for other industrial cases.

Automotive and aerospace components, utensils, and many other products are manufactured by a forming/drawing process on press machines of very thin sheet metal, 0.8 to 1.2 mm. It is imperative to study the effect of all involved parameters on output of this type of manufacturing process. This book offers the readers with application and suitability of various evolutionary, swarm, and bio-inspired optimization algorithms for sheet metal forming processes. Book initiates by presenting basics of metal forming, formability followed by discussion of process parameters in detail, prominent modes of failure, basics of optimization and various bioinspired approaches followed by optimization studies on various industrial components applying bioinspired optimization algorithms. Key Features: • Focus on description of basic investigation of metal forming, as well as evolutionary optimization • Presentation of innovative optimization methodologies to close the gap between those formulations and industrial problems, aimed at industrial professionals • Includes mathematical modeling of drawing/forming process • Discusses key performance parameters, such as Thinning, Fracture, and Wrinkling • Includes both numerical and experimental analysis

By the proposed probabilistic design approaches, deeper understanding about the relationship between process variables uncertainties with the part qualities is achieved. Ultimately, the process output variability could be reduced, defect rates could be minimized and product quality would be improved.

"Analysis and Optimization of Sheet Metal Forming Processes comprehensively covers sheet metal forming, from choosing materials, tools and the forming method to optimising the entire process through finite element analysis and computer aided engineering. Beginning with an introduction to sheet metal forming, the book provides a guide to the various techniques used within the industry. It provides a discussion of sheet metal properties relevant to forming processes, such as ductility, formability, and strength, and analyses how materials should be selected with factors including material properties, cost and availability. Forming processes including shearing, bending, deep drawing, and stamping are also discussed, along with tools such as dies, punches and moulds. Simulation and modelling are key to optimising the sheet metal forming process, including finite element analysis and computer aided engineering. Other topics included are quality control, design, industry applications and future trends. The book will be of interest to students and professionals working in the field of sheet metal and metal forming, materials science, mechanical engineering and metallurgy"--

Over the last 15 years, the application of innovative steel concepts in the automotive industry has increased steadily. Numerical simulation technology of hot forming of high-strength steel allows engineers to modify the formability of hot forming steel metals and to optimize die design schemes. Theories, Methods and Numerical Technology of Sheet Metal Cold and Hot Forming focuses on hot and cold forming theories, numerical methods, relative simulation and experiment techniques for high-strength steel forming and die design in the automobile industry. Theories, Methods and Numerical Technology of Sheet Metal Cold and Hot Forming introduces the general theories of cold forming, then expands upon advanced hot forming theories and simulation methods, including: the forming process, constitutive equations, hot boundary constraint treatment, and hot forming equipment and experiments. Various calculation methods of cold and hot forming, based on the authors’ experience in commercial CAE software for sheet metal forming, are provided, as well as a discussion of key issues, such as hot formability with quenching process, die design and cooling channel design in die, and formability experiments. Theories, Methods and Numerical Technology of Sheet Metal Cold and Hot Forming will enable readers to develop an advanced knowledge of hot forming, as well as to apply hot forming theories, calculation methods and key techniques to direct their die design. It is therefore a useful reference for students and researchers, as well as automotive engineers.

Metal forming is a process that transforms a simple shape of a workpiece into a predetermined complex shape through the application of compressive/tensile forces exerted by dies. In the design of a forming process, the only factors that are known are the final component shape and the material with which it is to be made. Then the engineer has to design a process to make defect-free product, subject to limitations of shape, material properties, cost, time, and other such factors. The design cycle can be enhanced if performance sensitivity information is available that could be used with any commercially available finite element software. Hence, this research investigates the analytical continuum-based sensitivity analysis method using boundary integral and material derivative formulations. Sensitivity derivation starts by obtaining an identity integral for the non-linear deformation process. Then the adjoint problem is introduced to obtain an explicit expression for the sensitivity of the objective and constraint functions. The applicability of sensitivity analysis is demonstrated through a steady-state metal forming process. In conventional optimization all the parameters are considered as deterministic and constant. However, in practice, they are prone to various uncertainties such as variations in billet geometry, die temperature, material properties, workpiece and forming equipment positional errors, and process parameters. A combination of these uncertainties could induce heavy manufacturing losses through premature die failure, final part geometric distortion, and production risk. Identifying, quantifying, and controlling the uncertainties will reduce risk in the manufacturing environment and will minimize the overall cost of production. Hence, in this research, a robust design methodology is developed by considering the randomness in the parameters. The developed methodology is applied for die shape optimization of an axisymmetric extrusion. Die angle and spline through points are the design variables; friction factor and ram velocity are considered as random parameters. The optimization problem is formulated to minimize the exit velocity variance by placing constraints on average strain and variance. Further, the solutions of reliability-based optimization are compared with deterministic-based optimization solutions. The results herein indicate that the robust design solution gives better product quality and reduces the total exit velocity variance.

The proposed numerical and analytical models provide the designer with powerful tools to rapidly and accurately assess the manufacturability of the desired part.