Stacking Sequence Effects on Fatigue Intra-laminar Damage Progression in Composite Joints
- PDF / 1,601,645 Bytes
- 25 Pages / 439.37 x 666.142 pts Page_size
- 83 Downloads / 167 Views
Stacking Sequence Effects on Fatigue Intra-laminar Damage Progression in Composite Joints A. Riccio & G. Mozzillo & F. Scaramuzzino
Received: 6 April 2012 / Accepted: 12 April 2012 / Published online: 1 May 2012 # Springer Science+Business Media B.V. 2012
Abstract In this paper the effects of the stacking sequence on the fatigue intra-laminar damage accumulation in pinned composite joints is investigated. A fatigue damage propagation numerical model based on gradual material degradation rules and Hashin fatigue failure criteria is formulated, implemented in a finite element platform and then used to simulate the intra-laminar fatigue damage evolution in the analysed composite joints. The model has been preliminary validated against literature experimental data in terms of s-n curves providing confirmation of its effectiveness in predicting the joints fatigue life. Different stacking sequences: zero-dominated, quasi-isotropic, cross-ply with different 0 ° and 90 ° plies distributions, have been considered when investigating the influence of the stacking sequence on the fatigue behaviour of the joints. The simulation of the joints’ fatigue life provided detailed information on the intra-laminar damage mechanisms on-set and evolution related to fatigue gradual degradation of material stiffness and strength for different values of the applied maximum stresses. Keywords Fatigue . Damage accumulation . Joints . FEM
1 Introduction During the service life of composite structures, degradation of material properties under fatigue contributes to establish the actual mechanical damage and its evolution laws influencing composite structures lifetime. Over the past years, most of the damage tolerant concepts experienced on metals have been straightforwardly applied to composites. However, the use of these concepts, due to the lack of robust numerical tools for composite structures fatigue damage tolerance and lifetime prediction, has led to over-conservative designs and extensive prototype testing, not allowing to exploit the full potential of composite materials in terms of costs and performances. Indeed, A. Riccio (*) : G. Mozzillo : F. Scaramuzzino Department of Aerospace and Mechanical Engineering, Second University of Naples, via Roma n 29, 81031 Aversa, Italy e-mail: [email protected]
250
Appl Compos Mater (2013) 20:249–273
relevant differences exist between metals and composites damage behaviour when subjected to fatigue loading conditions. In metals the phase of gradual and invisible deterioration lasts almost throughout the whole lifetime and no significant reduction of stiffness can be observed during the fatigue process. Only in the final stage of the fatigue process, the onset of one or more small growing and coalescing cracks takes place producing in a short range of time larger cracks which lead to the final failure of the structural component. The fatigue behaviour of fibre-reinforced plastic composites (CFRP), mainly due to their heterogeneous and anisotropic nature, is completely different. In the fi
Data Loading...
