Optimization of the Local Failure Design of Carbon-Fibre Epoxy Composite Curved Plates

Abstract

This thesis presents the optimization of the local failure design of Carbon-Fiber Epoxy Composite used in the manufacturing of the curved plates. As relatively new and reliable material carbon fiber can be used in different industries and fields, for instance oil and gas industry, with aim to optimize the design of the manufactured models and reduce the possibility of failure to occur in curved plate model structures. Using ANSYS Workbench 2020, a case study of local failure check is investigated. Thus, the thesis meets its main objectives as the simulation of the local failure in curved plate components helps to indicate main parameters which affects the model most and find parts of the model which are influenced by loads with the high risk of failure. This can affect the process of the manufacturing of structure main parts. The dissertation gives the explanation about the correlation and determination study as well as the response surface methodology in order to optimize the local failure design and further design of the curved plate components. The curved plate is subjected to high pressure and force. The engineering properties of used material and models, geometries, boundary conditions, loads and meshes are the input parameters and carried out using Static Structural tool and ACP process in ANSYS software. Output parameters are optimized values of failure criteria. Studies of correlation and determination matrixes are investigated to find parameters which affect the results. The Spearman correlation with different sample sizes is used to define and check the design parameters with the highest correlation and determination coefficients. These parameters are used for further study of the response surface. The result of correlation reflects that thickness of the model and applied pressure are strongly correlated with the predefined failure criteria. Thesis indicates the main design parameters which affect the curved plate and can lead it to the failure with critical values of the failure criteria. The model gives the area where the failure can be observed. With identifying the impact and main correlations, the critical step in design optimization is done. As the next step of the further design optimization process, response surface is investigated. The response surface methodology provides more accurate results of the failure criteria and gives precise information about the outcome parameters. The quality of the response surface varies with different response surface types and size of the response surface itself. Comparison studies of different response surface types results are investigated in this dissertation. The conclusion provides information about response surface results with small failure criteria values and optimal design parameters values. This provides the safe design of the curved plate model with the stiffeners.