Overcoming Effects from Environmental Temperature on the Natural Frequencies of Cable-strut Structures
Nasseradeen Ashwear *
Department of Mech., Faculty of Engineering, Misurata University Misurata, Libya.
Haithem Elderrat
Department of Mech., Faculty of Engineering, Misurata University Misurata, Libya.
Mahmud A. Eljaarani
Department of Industrial & Manufacturing Engineering, Faculty of Engineering, Misurata University Misurata, Libya.
*Author to whom correspondence should be addressed.
Abstract
The changes in dynamic properties such as natural frequencies and mode shapes are used in vibration health monitoring as tools for assessing the structures health status. They are, however, also affected by environmental conditions like wind, humidity and temperature changes. Of particular importance is the change of the environmental temperature, and it is the most commonly considered environmental variable that influences the vibration health monitoring algorithms. This paper discusses how cable-strut structures can be designed such that their first natural frequency is less sensitive to the temperature changes. The optimization problem is solved by using a genetic algorithm. The level of pre-stress can be regulated to achieve the solution, particularly when a symmetric self-stress vector is chosen.
Keywords: Cable-strut, Self-stress, Temperature effects, Optimization, Structure health monitoring, Vibration health monitoring.