Study On Wind Load Simulation In Forest And Finite Element Simulation Of The Tree’s Wind Resistance

Wind disaster caused great amount of financial lost around the world annually. Through the research of the structure characteristics and mechanical response of trees to wind load, a deeper understanding of how the tree is destroyed by the wind and the vulnerable parts of the tree structure can be get thus to take measures to enhance tree’s stability. Black Pinus chose as our main research object, which used as coastal protection forest. Then develop the tree’s finite element model which base on the data such as tree height, breast diameter etc. and start the loading experiments.This research combines simulation of wind’s time history, tree’s finite element modeling and analyzing of forest characteristics to study wind resistance of single tree. Then using the information of the stand to value the stability of a given forest area. According to the data we simulate the reaction of the Black Pinus under several work conditions whose wind load related to the wind level to study the tree’s wind resistance, probably damage type and vulnerable section then to propose some methods which can improve tree’s stability. We use ANSYS to build our model and through the help of APDL method, we use command stream file to confirm this progress is rapid and accurate. Also, we use linear filtering method to calculate the random time history wind load then we set the work conditions to realize multi-operating condition. Finally we compare the stress, displacement to know the tree’s mechanical response and stability. Due to the wood’s mechanical characteristics, its shear strength is less than tension strength and bending strength, and the stress contour shows that the shear strength is the main factor to judge the tree’s wind resistance ability. The failure sections locate at the connection between stem and branches or branch and branch, or on the stem at 50-70% of the tree height. Then we can take some measures such as regularly prune, reinforce the stem to improve tree’s stability so as to reduce the losses in a forest caused by wind disaster.