The Hadley Group
Hadley Industries PLC’s core business is manufacturing cold roll formed products, primarily to the building and construction industries. The company developed and patented a unique cold forming process known as UltraSTEEL® which significantly improves mechanical and structural properties of the strip steel by imparting a dimpling pattern prior to the roll forming operation. The geometry is much too complex to determine the structural properties of the end product based on analytical calculations alone, and it could cost $30,000 to $150,000 for tooling to manufacture the part so its properties could be physically measured.
Hadley addressed this challenge by using Marc nonlinear finite element analysis software to predict the highly nonlinear changes in geometry and material properties that occur during the UltraSTEEL® process, cold roll forming and secondary processes. “Marc overcame problems seen with other finite element software packages such as nonconvergence and provided reliable and consistent results that matched experimental measurements,” said Dr Martin English, Design and Development Manager for Hadley. “The ability to accurately simulate the process and quickly determine its performance in customer applications has been responsible for a substantial increase in sales volume estimated to total over $4 million over the next three years.”
Complex and interrelated nonlinear changes in contact, geometry and material properties occur during the UltraSTEEL® process and subsequent section forming and secondary operations. “The simulation challenge involves both accurately simulating these processes as well as applications under loading,” Nguyen said. “This requires simulations that connect to previous or subsequent simulations to perform continuous processes while taking into account the changes in geometry, material and structural properties of the materials. An important advantage of Marc in this regard is its PRE STATE procedure which can be used to transfer the geometry of the dimpled strip together with its material data including stress/strain data generated from the dimpling process into the subsequent simulations such as the cold roll forming process.”
The ideal approach is to simulate the entire chain of processes as a sequence from start to finish: 1) the dimpling process that deforms a flat steel strip into a dimpled strip, 2) the cold roll forming process that produces the desired section, and 3) additional processes such as shear cutting and applications such as products under tension, bending, compression loads, etc. The geometry and material data of the dimpled strip are transferred from one process to the next in a closed loop. This approach is practical for small sections of dimpled products and optimizing the dimpling process itself. However, the models of the rolls and dimpled strip can contain tens of millions of elements for larger models so transferring the stress/strain data between each of the stages becomes very complicate and time-consuming, resulting in high computational costs.
“The reliable and consistent results provided by Marc make it possible to accurately assess the applicability of UltraSTEEL® for existing and new products in a short time frame at a low cost,” English concluded. “The accurate simulations have enabled Hadley to make and substantiate technical claims regarding the benefits of the process. As a result the company has increased its sales of UltraSTEEL® products and also generated additional revenue by increasing licensing of the process amounting to an estimated $4 million over the next three years.”