Stretch forming is a type of metalworking most commonly used in aerospace applications. During the stretch forming, or wrap forming process, metal sheets or extrusions are stretched to exceed their inherent elastic limit, and then wrapped and formed around contoured dies and profiles to create the desired shape. This “stretching” process results in an increased material yield strength and a stronger finished part.
Stretch forming can produce parts of varying complexity, from a simple curved part such as an aircraft skin to one with intricate geometries consisting of non-uniform cross sections. Most leading edge parts, joined structural sections, and contoured trim are created using the stretch forming process.
Beckwood manufactures Triform’s next generation sheet and extrusion stretch forming machines in configurations tailored to each user’s application. The Triform Stretch Forming line draws from Beckwood’s deep reservoir of precision hydraulic press control experience, creating highly accurate and consistent forming results.
Features of Beckwood’s Triform Stretch Forming Machines
- Synched or independent arm actuation
- Programmable pressure and position cycles facilitate both traditional and tangential stretch forming
- ‘Closed-loop’ control system allows precise, repeatable tension and angle control during operation: Arm Angle Control (+/-0.5 degrees) / Tension Force Control (+/- 2% of full scale)
- Accurate, uniform tension force throughout the cycle minimizes wrinkling
- Programmable post-load cycle minimizes material spring back and increases the yield strength of material
- Built-in recipe functionality allows users to save proven cycle parameters for guaranteed repeatability and decreased set-up time
- Manual control mode gives the operator direct control over the cycle profile during new part development
- Supplemental accessories such as heat integration for high strength alloys and hydraulic joggle rams for setting bends in the formed extrusions can be incorporated as needed
Beckwood engineers each structure for Infinite Life using FEA design analysis software. Our robust stretch forming designs feature top-quality standard components from leaders in the industry and are outfitted with Beckwood’s PressLink system for remote connectivity to the factory, for fast, efficient support.
Beckwood is an official partner of ESI, the provider of PAM-STAMP Forming Simulation Software. In addition to providing highly accurate simulations of traditional forming and drawing processes, PAM-STAMP offers tremendous advantages to operations using Triform sheet hydroforming presses, stretch forming machines, ring expanders, and hot joggle presses. Part quoting, new part development, tooling design, and sales efforts are all aided by PAM-STAMP simulations.