Wind tunnel test on vibration reduction of forest by spring damper in casing pipe

In order to reduce wind-induced vibration damage of forest, four spring dampers in casing pipe were developed based on vibration reduction theory in this article, and wind-induced vibration reduction of four Populus alba var. pyramidalis specimens were carried out separately by them. In a self-made simple wind tunnel, contrast tests of vibration reduction with/without the action of damper were carried out by simulating natural wind environment; comparative characteristics curves of wind-induced dynamic strain, wind-induced dynamic displacement, wind-induced dynamic speed and wind-induced dynamic acceleration response were obtained. Results showed that wind-induced dynamic response of forest could be measured by strain gages pasting on forest and charge accelerometer installed on forest, and wind-induced dynamic peak response, such as strain, displacement, velocity and acceleration, could be reduced effectively by spring damper in casing pipe fixed on forest, and the effect of vibration reduction of forest equipped with spring damper in casing pipe was very good. Spring damper in casing pipe developed in this paper has features such as relative simple structure, low cost, and good weather resistance, and therefore it is suitable for popularization over large areas, especially suitable for wind disaster protection of forest in difficult stand conditions. Wind disaster protection of forest are carried out through the use of spring damper in casing pipe developed in this paper, and the methods in this paper give a new approach to wind disaster protection of forest.