Abstract: Presence of nonlinearity in the structure can affect the global dynamic behavior. Hence detection of nonlinearity has a greater significance in the context of structural health monitoring. In this paper we present a technique based on principal component analysis for detecting the presence of nonlinearity in the structure. The angle between response subspaces is taken as a feature to detect nonlinearity. The major advantages of the proposed technique is that it uses only acceleration time history data and can be used with ambient vibration data, which is ideally suited for civil structures. Numerical simulation studies have been carried out using a cantilever beam with nonlinear cubic stiffness attachment. Studies presented in this paper clearly indicate that the proposed technique is robust.

• Publication Date: 25-May-2014
• DOI: 10.15224/978-1-63248-028-6-03-50
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Abstract: Mostly steel are heat treated under controlled sequence of heating and cooling to modify mechanical properties to meet desired requirements of engineering applications. The main objective of this study is to investigate the effect of different annealing temperature on the impact toughness of low carbon steel grade Fe-415D. Sample of steel was purchased from local market. The steel samples were heat treated (annealed) in electric muffle furnace at different temperature level and holding times and then cooled in furnace. The toughness properties of the heat treated and untreated samples were determined using impact testing machine. Results showed that toughness properties of steel can be changed and improved by annealing heat treatment process

• Publication Date: 25-May-2014
• DOI: 10.15224/978-1-63248-028-6-03-51
• Views: 0
• Downloads: 0