Research On Optimal Sensor Placement Of Health Monitoring On Grid Structures

Large-span spatial structures have been applied widely in many fields, with new forms and systems frequently developed by civil engineers. And such large-span spatial structure is usually applied to sports venues, airport terminal buildings, Convention and Exhibition Centers, theaters and other public service facilities which usually people gathered in and used for the major event venues. Therefore, during the construction and service period, the health monitoring and diagnosis under various disasters and damages, early warning and identification research of the spatial structures, are not only of great academic value, a more important practical significance. On the current terms, at home and abroad the research and application system for health monitoring of spatial structures have not yet formed. this paper, based on the research and application of structural health monitoring in civil engineering in recent years at home and abroad, focusing on the most important issue of health monitoring - the optimization of sensor Layout. According to the characteristics of spatial grid structure, analyze its optimization principles and program corresponding programs.First of all, this paper starts with the brief introduction of the perspective, the most basic mode of technology and dynamic features of the issue based on the mathematical aspect. Then represent some representative principles of the sensor optimization, which focus on the basic principles of four traditional types and the energy -based modal -guarantee type. After that, represent four typical optimization algorithm, non-linear programming optimization methods, sequence, inference algorithms, and random category method. The simulation of biological and physical processes in the method of sensor layout which is non-traditional optimization algorithm developed in recent years occupies an important position, which, the genetic algorithms gets the most extensive application and study. Based on energy and modal theory ensures, the use of genetic algorithm makes the sensor layout algorithm into the available process modules. In this paper, also, give a detailed briefing to the core algorithms of the very program. If the number of sensors is given, procedures, under the premise of modal theory, can calculate the best locations of the strain sensors layout in the structure. For the bar structure, import the information of strain mode. For the beam structure, import the information of the curvature mode.Secondly, a detailed analysis of conventional space grid structure of the sensor layout issues is given. Several examples of calculation results show that in the symmetrical structure, the optimization is symmetrical, particularly the sensors is few. In addition, the optimization result with its succession coincides with the theoretical optimum logic. Through the example of flat-panel grid can be seen that in its strain sensor layout, strain sensors should be settled on lower chord in priority, followed in considering the upper chord, and web member followed. When selecting the optimal area, in considering the low-end vibration mode, the strain sensors should be settle in the largest static deformation regional first. When considering the involvement of higher-order mode, the strain sensor layout should be near the bearings. The single shell, also complies the rules.Finally, give a brief introduction to the core electronic components of the wireless strain sensing system, and each module gets an independent design, debug respectively. And then integrates the wireless strain sensors based on the digital interface.