Analysis of the performance of a new concept for automatic draping of wide reinforcement fabrics with pre-shear:A virtual prototyping study

The layup process of large composite structures made from dry reinforcement fabrics is considered. One such structure is a wind turbine blade, for which the current draping process is mostly manual. Automating the draping process will, therefore, lower the costs. Based on a literature review, a new concept is synthesized and analyzed using an advanced finite element model with rigid multi-body kinematics and a dedicated material model for the fabric. The material model is calibrated using experimental coupon tests, i.e. the bias-extension test (shear) and Peirce's cantilever test (out-of-plane bending). The concept is analyzed numerically by means of a simple parameter study and draping test cases on a flat mold as well as a general double-curved mold. The simulation results show that the concept is feasible for the draping operation and is thus qualified for the subsequent physical prototyping.</p

Simulation based draping of dry carbon fibre textiles with cooperating robots

Carbon fibre-reinforced plastic (CFRP) is a promising material for aircraft and other lightweight applications. To be competitive with low-cost metal based solutions highly effective and flexible production technologies are required. For this purpose production systems comprising automated fibre placement or automated tape laying technology are on the market for several years and widely spread. However, there is still a lack of automated systems capable of producing preforms efficiently and flexibly from textile semi-finished goods. Non-crimp fabrics (NCF) and weaves have to undergo considerable shear and reshaping during the layup of 3D-curved preforms in order to properly fit the 2D cut pieces to the moulds. At the Center for Lightweight Production Technology (ZLP) a digital and automated process for the easy draping of large NCF and weave cut pieces with several robots according to the previous draping simulation has been set up and tested in a robotic work cell. The details of converting the draping simulation into correct and easy to setup motions for cooperating robots and how to execute the entire process autonomously, i.e. without teaching the robots, are described. On the basis of preliminary tests the system’s capabilities on a large scale demonstrator part resembling an airplane’s rear pressure bulkhead are evaluated. An overview of the system’s architecture from simulation based planning to detecting, correct gripping, collision free autonomous transport and laydown of the cut pieces is also given

Autonomous Composite Production by Robotic Pick & Place

During the last decade the DLR Center of Lightweigth Production Technology (ZLP) in Augsburg investigated the potential of the autonomous production of composite parts by means of pick and place executed by industrial robots. Starting from conventional teaching the research focus was extended to the development of technology bricks for computer vision based gripping, automated derivation of grip- and drop coordinates from CAD data, digital process description and workflow, autonomous cut-piece transfer by means of collision free path planning and a multi-robot synchronization and execution layer. The technology bricks are enriched by a process data acquisition system and controlled by a manufacturing execution system embedded into a high-level process control system. In this work we give an overview of the developed technologies and achievements based upon several use cases from the field of composite production