Response of composite laminates under out of-plane loading

• Autores: Ahmed Wagih Abdallah Abdel Hady
• Directores de la Tesis: Jose Norberto Blanco Villaverde (dir. tes.), Pere Maimí Vert (codir. tes.)
• Lectura: En la Universitat de Girona ( España ) en 2018
• Idioma: español
• Tribunal Calificador de la Tesis: Frédéric Laurin (presid.), Jordi Renart Canalias (secret.), Giuseppe Catalanotti (voc.)
• Programa de doctorado: Programa de Doctorado en Tecnología por la Universidad de Girona
• Materias:
  • Química
    • Química macromolecular
      • Polímeros compuestos
• Enlaces
  • Tesis en acceso abierto en: TDX
• Resumen

  • The main objective of the thesis is to provide a reliable scaling tool to predict the response of composite structures under out-of-plane loading by testing small coupons. This global objective cannot be achieved without understanding the damage mechanisms and their sequences in composite laminates under out-of-plane loading. The main objective of the thesis has been achieved by considering three different sub-objectives. The first sub-objective is focusing on understanding the damage mechanisms and their sequences in composite laminates made of different ply thicknesses. The damage mechanisms are almost the same for the different ply thicknesses considered. However, the interaction between the damage mechanisms changes by changing the ply thickness.

    The second sub-objective focuses on understanding the influence of the laminate design parameters, mismatch angle between plies and ply thickness, on the response of composite laminates under out-of-plane loading.

    In the third sub-objective, the contact problem of a stiff spherical indenter with a composite plate was simulated with a 2D axisymmetric model implemented on a commercial software. A parametric study was carried out numerically to study the effect of the different parameters on the force-indentation response. The results show that the indentation response of an orthotropic laminate is material independent and that it strongly depends on the laminate thickness.

    Finally, the scaling tool to predict the response of composite structures under out-ofplane loading is implemented in two steps. First, an analytical model is proposed to predict the quasi-static indentation response during the elastic and delamination regime up to fiber failure. The model is able to predict the load-displacement and the delamination area-displacement responses. Based on a linear relationship with respect to the applied displacement, the model is able to predict the delamination area up to fiber breakage in a good agreement with the experimental observations.