3-Dimensional Forming of Thick Plates - A Comparison of Deep Drawing and an Approach of Rolling and Bending within a Single Proces

A variety of industries require certain 3-dimensional formed thick plates, for example in shipbuilding for shell plates. Nowadays the production of curved ship plates is mainly based on the experience of the worker and is performed manually. The results are good and sufficient for the heretofore use in industry, taking into account that the number of curved plates with the same geometry is quite small. Moreover thick plates with a variable thickness are used for instance as so called longitudinal profiles for bridge building. Currently the combination of curved plates with variable thickness does not meet a wide range of applications. But it has high potential in future. In modern shipbuilding this kind of plates offers special applications with a broad scope, e.g. reduction of weight. Renewable energies are another huge market in future. Today, wind turbines are mostly made of glass or carbon fiber. The manufacturing process leads to high precision and quality of the final product. Nevertheless, this fabrication method of rotor blades is very cost intensive and its production technology is not the best in terms of recyclability. In addition to its good reusability, the handling of steel is well known and its fabrication is inexpensive. Due to these facts an idea of rotor blades to be produced from steel arose. However, when desiring a huge output of a product with the same geometry a manual approach is inappropriate. A new process should be repeatable and within a certain accuracy. Deep drawing of the product is a natural choice but is not used for thick plates of enlarged sizes until now. This paper presents a comparison of deep drawing and a new approach. The developed process is based on a superposition of flat rolling and 3-dimensional bending. A major advantage of combining these steps is the opportunity to deliver formed plates with a variable thickness. This paper presents numerical simulations of deep drawing and rolling processes. The results are compared in terms of practicability for the production of rotor blades.