Browsing by Author "Arachchige, Buddhi"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
Item Open Access Post impact analysis of damaged variable-stiffness curved composite plates(Elsevier, 2017-01-18) Arachchige, Buddhi; Ghasemnejad, HessammaddinThis research studies the post impact response of damaged area of variable stiffness curved composite plates. Varying thicknesses of sections is widely found in aerospace and automotive composite sub structures. In this regard, the impact response of this geometry characteristic has to be studied in thin-walled structures. In our model, a removal of ply technique is used to represent damaged region within a curved panel, thus degrading the stiffness in that area is considered in the theoretical models. A summation of spring-mass systems is used in the modelling of damaged variable stiffness plate to analysis post impact behaviour of these structures. The theoretical force-time results are also compared with the relevant finite element outcomes in LSDYNA. The comparison establishes a good prediction capability of the proposed model.Item Open Access Theoretical approach to predict transverse impact on variable stiffness curved composite plates.(2017-09) Arachchige, Buddhi; Ghasemnejad, HessamComposite materials are widely used in the industry nowadays due to its attractive advantages such as been lightweight, high strength to weight ratios and ability to design and manufacture complex shapes. However, one of the main disadvantages are that composites are susceptible to impact damage and this is an issue that needs to be addressed. The main interests in this research lies in the analysis of curved variable stiffness composite plates under low velocity impact conditions. There is a need to develop a detailed analytical model to predict the low velocity transverse impact of curved variable stiffness panels. An analytical model is a useful tool in obtaining an initial understanding of the behaviour of such structures under impact loading due its efficient and cost effective nature. Analytical models do not usually require high computational processing power when compared to advanced numerical models and therefore is a time-saving technique. The proposed analytical model would be useful for the composite modelling and manufacturing industry since it is robust, efficient and cost effective when compared with experimental tests or numerical models. The major research gap identified was the need to contribute to the research on analytical modelling of curved composite shell structures and extend the study to sandwich structures as well. The main novelty and contribution of the present research is the development of an analytical model to study impact response of variable stiffness curved composite plates and sandwich plates. The result of the work can be used as a tool to understand the low velocity impact response of curved composite shell structures, i.e. to study the effect of various parameters such as layups, velocities, impact masses, geometry, boundary conditions, etc. affect impact damage response. Analytical methods provide an initial view on the behaviour of a composite structure and the need to build an analytical tool to predict the impact response of variable stiffness composite plates was identified. First order shear deformation theory coupled with two degree of freedom mass-spring system was used to derive analytical force functions for the variable stiffness plate. Contact force histories were plotted to study the effect of geometry, layups and impact velocity on the impact response of variable stiffness curved composite plates.Item Open Access Theoretical approach to predict transverse impact response of variable-stiffness curved composite plates(Elsevier, 2015-12-14) Arachchige, Buddhi; Ghasemnejad, Hessam; Augousti, Andreas T.This research studies the low velocity impact behaviour of variable stiffness curved composite plates. Since variable thickness within composite structures is recognised as an important factor on the performance of the structures, significant mathematical modelling to predict the impact response of these types of structure is essential. Varying thicknesses of sections is widely found in aerospace and automotive composite sub structures. It has been observed that changing of geometry of these sections can vary the dynamic response of anisotropic composite structures under a range of monolithic and dynamic loading conditions. Here we have used first order shear deformation theory to predict the contact force history of curved composite plates and the same approach was used for variable thickness composite plates, which provides the main novelty of this research. It was shown that the model developed here is capable of successfully predicting the response of variable stiffness composite plates with a range of layups and geometry designs under impact loading conditions.