1. Design for Manufacturing Accurate Skin Panels from Fibre Metal Laminates Background Fibre metal laminates (FMLs) as a new hybrid aerospace material has found applications in structural parts of aircraft like fuselage panels. Different manufacturing processes like cure, adding doublers and splices, cut-outs and post-cure produces residual stresses and shape deviations. To have high performance and accurate skin panels made of FMLs and finally make massive production of FMLs possible without manual action and corrections, it is needed to have models that describe the manufacturing- induced phenomena and predict the final mechanical and geometric state of the structure. In this regard, no considerable research is done on FMLs. The most relevant works available are on some common processes on full composites. If we can model these processes and predict the stresses and distortions, we can reduce them by designing revised layup tools. Experimental Strategy Approach 1: Direct/indirect measurement of residual strains of cured samples Measurement of: Curvature Calculation Residual Strain & Stress Residual strainsCalculation Residual Stress Ply removal Measuring T Stress-Free Approach 2: Monitoring/measurement during cure Cure-monitoring of: Curvature Interrupted cure Calculation of Residual Strain & Stress Residual strainsCalculation Residual Stress Embedded strain gages or fibre optic sensors Research Methodology Phase 1: Introduction and Literature Review Phase 2: Understanding and Measurement of Residual strains (Distortion) in Simple Configurations Phase 3: Complete Cure Modeling and Measurement of Residual Strains (Distortion) During Manufacture of an FML Phase 4: Residual Stress (Distortion) in FML Skin Panels, Including Splices, Doublers and Ply-Drop-Off Phase 5: Experimental Study and Modeling of Residual Stress-Distortion in post-cure Processes of FML Skin Panels Phase 6: Combining Previous Phases to Achieve a Predictive Model for the Whole Process Manufacturing Processes Generate Distortion Manufacturing Processes and effects on Residual Stress (Distortion) of FMLs PhD Candidate: Morteza Abouhamzeh Department: ASM Section: Structural Integrity & Composites Supervisor: J. Sinke Promoter: R. Benedictus Start date: 10-02-2012 Funding: Cooperations: Aerospace Engineering Preparation Including: Cutting sheets and layers Forming-layup Main Cure Cycle - Cure-Cooldown ( Chemical & Thermal Parts ) - Splices/Doublers Important Factors: Thickness Anti-symmetry Cure cycle (P,T,t) Resin material Fibre volume gradient Remove from Layup To ol (Tool-Part Interaction) Important Factors: Thickness Surface roughness Layup tool material 2nd Cure Cycle Including: Attachment of stiffeners, doublers and stringers Trimming & Cut-out Final Integrated Panel Manufacturing FMLs for Fuselage Model Development Current Stage: Modeling:Cure (cool-down process): Linear elastic modeling (sym./unsym. GLARE panels) Nonlinear (large-displacement) elastic Experiments: Manufacturing some simple laminates and measuring curvature and strains Determination of stress-free temperature (using curved unsym. panles) Determining curvature and residual strains by eliminating one ply from a symmetric FML