Overview
This blog explores the present state of the composites design applied with the DFM approach.
Abbreviations
AFP - Automated Fiber Placement
DFM - Design For Manufacturing
AFP Composites Design Approach
AFP manufacturing process kinematics, process parameters, and gathered data from the process are constantly used to optimize the design of the part, Contrary to other composites layup processes where the laminates are made either by complete sheets or by continuous processes, AFP works like true Additive manufacturing technology, enabling the placement of right material in the right shape, orientation, etc. This leads to a solution space that is very vast for a manual designer to explore. Thus generative designs that is constrained by AFP process limitation populate the solution space. Selecting the most suitable solution and producing it a few times, can provide an infinite improvement loop from the process data, [Link]
The cost/weight optimization approach
The cost/weight optimization framework works by accounting for the material consumption and process time, it is trying to find tradeoffs between the structural
performance of a component and its manufacturing cost. The methodology is aimed to be used in the preliminary design phase; thus, the output of the optimization is neither detailed manufacturing documentation nor a ply book. The introduction of a draping model in this phase is rather a way to
Provide the cost model with more detailed manufacturing knowledge
To perform a structural analysis with fiber angles closer to reality and producibility constraints
To show that the choice of the draping strategy can influence the cost and weight balance of a component. [Link]
Coupon to FEA Approach
After the mechanical characterization of the CFRP material, it is possible to calibrate the numerical material model, to properly design and perform experimental tests on
thin-walled tubular structures. The simplified tested model is later extended to the conical crash component. In such cases, manufacturing is always assumed to be hand layup work [Link]. A similar approach is also touted by commercial designers as well in the automotive industry [Link].
Test-cost optimized design framework
Optimization of manufacturing cost, NDT cost, and the weight formed by a simplified version of the direct operating cost. It's a very academic framework and is very rarely used in commercial operations. [Link]
Design for Manufacturing strategy by SAAB Aerostructures
