Literature review Dissertation Example | Topics and Well Written Essays - 3500 words

Literature review - Dissertation Example Table of figures Figure 1 Evolution of materials used in structure construction (Balageas, et al., 2006) Figure 2 A schematic representation of coordinates and plate in lamb wave formation (Ryden, et al., 2004) Figure 3 propagation of Asymetric and Symetric lamb wave modes (NDT, 2012) Figure 4 Cross-section of a typical Contact transducer (Arnau & Vives, 2008) Figure 5 compact 3D laser vibrometer (Oliver, 2000) Structural Health Monitoring (SHM) Structural health monitoring can be defined as the process of implementing strategies aimed at identifying damages in engineering infrastructure. Damages, within the monitoring process, refer to changes occurring in the components and materials that could affect structural functioning adversely. The evaluation tools utilised ought to present non-destructive effects to the structures. In establishing the damage, past, present and future status of structures should be considered carefully (Farrar & Worden 2007). Changes with adverse effects to the functioning of the systems form the greatest concern referred as damages. The relevant changes should be quantifiable for classification as damages and their effects on the functioning of structures adverse. Motivations of SHM Structural health monitoring remains an essential process aimed at ensuring safety of engineering structures. Monitoring could be essential in identifying defects within structures, prompting appropriate corrective measure with the aim of rectifying the detected defects. This process might be carried out as part of routine maintenance procedures undertaken during the lifetime of engineering structures. Monitoring could therefore, precede planned maintenance procedures as it can assist in detecting changes within the structure that need rectification (Balageas et al. 2006). Necessary repairs to structures can be identified through monitoring before engaging the repairing teams. These processes can assist maintenance teams in identifying the required mainten ance procedures for different projects. The adverse effects of damages could escalate to a point where structures become classified as unusable. Slow accumulation of damage could drive structures to this stage referred as failure. The process of implementing monitoring strategies involves making structural observations, over period, using standardised measurements and analysis. The monitoring process should provide analytical information regarding the future functioning of the structure in relation to the anticipated ageing associated with time (Farrar & Worden, 2007). Since ageing of structures remain inevitable, monitoring the ageing process become crucial in minimising the possibility of structures collapsing unexpectedly. Monitoring the ageing process provides engineers with information that can be utilised when performing routine maintenance on structures. This information can also be utilised when constructing new structures through identification of problems that might occur as observed in existing structures (Fassois & Sakellariou, 2007). The ageing process could impose significant changes into materials; changing their characteristics. Modifications to materials can, however, be undertaken artificially through addition of relevant components. The general trend of modifying the materials shows changes from simple, natural materials to complex, auto-adaptive materials as indicated in the figure below. These adaptations remain essential in increasing adaptability of materials