Study On The Jumping Behaviour And Analysis On The Biological Material Mechanics Of Jumping Legs Of Locusts

The jumping insects have established excellent performance in jumping after billionsyears of natural selection. They can reach incredible height and distance in a short time,though they are small in size. The powerful jumping capability was provided by theirjumping legs, the structure of femur and tibia supply lots of energy for the jumping. Beforetaking off, the insects decrease the centre of gravity and compress the cuticle so that theenergy can be stored in the deformation of the cuticle, which provide about half of jumpingenergy. Consequently, it is necessary to study the cuticle feature of the jumping leg andaccordingly establish models of structure of jumping leg to provide basis for bionic studyof jumping insects.The locusts of jumping insects were studied in this study. The jumping process wasvideoed to obtain data after measuring the jumping characteristics of locusts. Based on thesedata, the pattern of jumping motion was analyzed in detail and expressed as function of time.The stress status, maximum value of stress and its position in the cuticle of jumping leg wasobtained and analyzed during the jumping. The results showed that the maximum stresspresented in the femur next to semi.lunar groove and the middle of tibia.To obtain the parameters of biological material, such as maximum load, maximumstress, strain and modulus, the mechanical tests on the tension and bending of joint, femurand tibia of jumping leg were conducted. The results showed that the modulus of cuticle washigh and then it was used for the simulation of mechanics. The structure superiorities offemur and tibia was also found in the following aspects: the existence of musculaturestrengthened the mechanical property of femur; the rotary inertia was increased as well; thecuticle feature of the jumping leg on bending surface was better than that in side surface forboth of the femur and tibia. The results also showed that the modulus of tibia was higherthan that of femur; the rotary inertia of tibia was less than that of femur because of thehollow structure of tibia, which contributed to the controlling of jumping leg and adjustmentof body position during jumping of locusts. Different test curves and destruction formspresented in the tests of mechanics, and the reason was identified.The point cloud of jumping leg structure was obtained through3D scanning to establishthe model of jumping leg using Imageware. The model was simplified for better fit forsimulating analysis, which was used in the simulation of mechanics using Ansys-workbench.While, the kinetic system of jumping leg was modeled using ADAMS, which primarilysatisfied the kinematic relation among each structure of the jumping leg and the parametersof dynamics. The movement parameters of each structure of the jumping leg were defined based on the function of motion aforementioned. The models were modified and improvedfor easy analysis through comparing the simulation results with the movement process ofjumping leg and related computing results.