Stretch bending is a metal forming process used to create curved or contoured shapes in sheet metal or other ductile materials. It involves stretching the material over a form or die while applying bending forces, resulting in a permanent deformation and the desired curved shape. This process is commonly used in industries such as automotive, aerospace, construction, and manufacturing for applications such as curved panels, tubes, or structural components.

Here’s an overview of the stretch bending process:

1. Material Selection: Choose a sheet metal or other ductile material suitable for stretch bending. The material’s ductility is crucial to accommodate the deformation required for bending without fracturing or tearing.

2. Forming Tool Setup: Set up the forming tool or die that defines the desired curve or contour. The tool typically consists of a curved surface that serves as a template for bending the material. The form may be made of steel, aluminum, or other materials depending on the specific application and required precision.

3. Clamping and Fixturing: Secure the sheet metal or workpiece onto the forming tool using clamps or fixtures to ensure it remains in place during the bending process. Proper alignment and positioning are critical to achieve accurate and consistent bending results.

4. Stretching the Material: Apply stretching forces to the sheet metal, typically using hydraulic or mechanical devices. The stretching force helps the material conform to the shape of the forming tool and undergo plastic deformation.

5. Bending Process: Apply bending forces to the material while it is being stretched. This can be achieved by using mechanical or hydraulic presses, rollers, or other specialized equipment. The bending force, applied in combination with the stretching force, causes the material to bend and take on the desired curved shape.

6. Deformation Control: Carefully control the amount of stretching and bending forces to achieve the desired curvature while avoiding excessive deformation or material failure. The process parameters, such as the force applied, the rate of stretching, and the bending speed, are determined based on the material properties, thickness, and curvature requirements.