Search Results for sheet-forming

Sheet forming failures divert resources from normal business activities and have significant bottom-line impact. This article focuses on the formation, causes, and limitations of four primary categories of sheet forming failures, namely necks, fractures/splits/cracks, wrinkles/loose metal, and springback/dimensional. It discusses the processes involved in analytical tools that aid in characterizing the state of a formed part. In addition, information on draw panel analysis and troubleshooting of sheet forming failures is also provided.

Sheet forming comprises deformation processes in which a metal blank is shaped by tools or dies, primarily under the action of tensile stresses. This article discusses the classification of sheet-forming processes for obtaining desired dimensional features. It describes different process-related developments, namely, superplastic forming of aluminum, forming of tailor-welded blanks, rubber-pad forming, and high-velocity metal forming. The article explains cost-effective approaches of evaluating tooling designs prior to the manufacture of expensive steel dies and dieless forming techniques such as thermal forming and peen forming. It provides information on the application of advanced high-strength steels, magnesium alloys, and various ultrafine-grain materials for superplastic sheet forming. The article concludes with information on the development and application of simulation, design, and control of sheet-forming processes.

Sheet-forming processes provide considerable geometric and material flexibility in meeting these requirements, and design of parts for sheet forming must take into account these benefits as well as the limitations of the processes. This article reviews the basic forming operations and their general geometric features. These operations include hole making, flanging, bead and rib forming, and stretching and drawing for shallow or deep recesses. The article illustrates the general approach to design for sheet forming and the considerations that must be made for material savings and manufacturing ease, in addition to part function. It concludes with information on reducing the amount of scrap in sheet-forming operations.

This article is a compilation of definitions of the terms related to sheet metal forming and fabrication.

This article provides an overview of the incremental sheet forming (ISF) process and discusses the process variations of ISF. These variations include single-point incremental forming, two-point incremental forming, and kinematic incremental sheet forming. The article discusses the machines and equipment used in the process and describes the process parameters, process mechanics, and process limits. It illustrates multistage forming strategies and summarizes difficulties that exist with regard to the finite-element process simulation of ISF process. The article also describes hybrid process variations, such as stretch forming and laser-assisted ISF.

This article discusses many of the processes and related considerations involved in the forming of superplastic sheet metal parts. It reviews the requirements for superplasticity and describes the characteristics of superplastic metals. The characterization of superplastic behavior includes the characterization of plastic flow, internal cavitation, and fracture behavior. Processing variables needed for the overall characterization of superplastic behavior are summarized. The article discusses the superplastic forming methods, namely, blow forming, vacuum forming, thermoforming, deep drawing, superplastic forming/diffusion bonding, forging, extrusion, and dieless drawing. It provides information on superelastic forming equipment and tooling. The article explains the thinning characteristics and quick plastic forming and its technological elements. It describes the manufacturing practice of the process. The article concludes with a discussion on the superplastic behavior in iron-base alloys.

This article discusses the tribology of three main sheet forming processes: deep drawing, bending, and shearing. For each process, the basic principle of the forming process is briefly explained. Tribological phenomena observed in each process, such as wear and galling, are presented. Common methods of using lubricants and coatings in sheet forming processes are also described.

Rapid prototyping (RP) techniques in the sheet-metal forming industry is developed to quickly test the form and fit of new sheet-metal products on a prototype basis as well as for production runs characterized by small lot sizes. This article provides an overview of some of the technologies used for RP and low-volume production of sheet-metal parts. It discusses low-cost tooling and flexible sheet-forming processes and reviews the various aspects of incremental sheet forming.

This article discusses the numerical simulation of the forming of aluminum alloy sheet metals. The macroscopic and microscopic aspects of the plastic behavior of aluminum alloys are reviewed. The article presents constitutive equations suitable for the description of aluminum alloy sheets. It explains testing procedures and analysis methods that are used to measure the relevant data needed to identify the material coefficients. The article describes the various formulations of finite element methods used in sheet metal forming process simulations. Stress-integration procedures for both continuum and crystal-plasticity mechanics are also discussed. The article also provides various examples that illustrate the simulation of aluminum sheet forming.

Simulation programs are becoming more effective tools in reducing the need for physical testing and the avoidance of costly downstream problems by solving the problems upfront in the early development stage. This article provides a brief review of the history and applied analysis of simple forming operations. It focuses on metal stamping simulation based on the finite-element methods or model (FEM) with emphasis on software tools using the three-dimensional FEM technology. The article discusses two aspects of particular importance in finite-element analysis of sheet forming and springback analysis: the type of solution algorithm/governing equation and the type of element. The article provides information on various models for material yield criteria.