Design Of Bionic Vibration Isolation Device Based On The Structural Of Goat Limb

The goat limb can effectively cushion the impact vibration from the ground during walking,running and jumping,and greatly reduce the harm of vibration to the brain,heart and other important organs.Through the study of goat limb structure,the internal structure and organizational functions of goat limb were clarified;the cushioning and vibration damping mechanism of goat limb was investigated by using multi-body dynamics simulation and finite element simulation analysis;various bionic vibration isolation devices for different working conditions were proposed based on the non-linear cushioning and vibration damping structure of goat limb:1.The internal structure and mechanical properties of the goat limbs were studied.The internal structure and constituent tissues of the goat’s front and hind limbs were dissected to study the shape,size,location,adjacency and function of the goat’s front and hind limbs.The changes of the main muscles when the limbs were stretched and compressed by external forces were studied,and the role of each muscle in resisting external forces was clarified.This indicated that the goat limb had nonlinear stiffness and could adjust its own stiffness characteristics according to the external load to protect its structure from damage.2.The cushioning and vibration reduction mechanism of the goat limb was investigated.Taking the knee joint of goat as the object of study,finite element simulation was used to investigate the cushioning and vibration damping mechanism of the goat joint and to clarify the role of each tissue.The simulation results showed that the articular cartilage played an important role in the cushioning and vibration reduction function of the knee joint,which reduced the damage to the femur of goats caused by external impact during walking and running;the meniscus and articular cartilage cooperated with each other to reduce the maximum stress on the femur by about90%.The limb muscles limited excessive translation and rotation of the leg bones after ground vibration impact,and played an irreplaceable role in the cushioning and vibration reduction function of the knee joint.The simulation results displayed that the goat limb had excellent lowfrequency vibration suppression effect under the synergistic effect of bone and muscle,and the vibration suppression effect became more and more excellent with the increase of vibration frequency.3.A bionic low-frequency vibration isolation device was designed inspired by the joint structure of the goat.The polygonal device was used to realize the cushioning and vibration damping function of the goat joint and the inertial element was introduced to achieve the excellent low frequency vibration isolation performance.The results of geometric relationship analysis showed that the vertical displacement of the bionic device was nonlinearly related to the deformation angle and horizontal displacement.The dynamics model of the bionic low-frequency vibration isolation device was constructed and its equivalent stiffness and equivalent resonant frequency were obtained.The influence of each device design parameter on the vibration isolation performance was analyzed.The resonant frequency of the bionic vibration isolation system based on the goat joint structure was 1.3 Hz,and the vibration isolation started to function when the vibration frequency exceeded 2.4 Hz.The low resonant frequency made the bionic device have excellent vibration isolation performance and a large range of vibration damping frequencies,which can be better applied in engineering practice.4.A large-stroke bionic nonlinear vibration isolation device was designed based on the goat limb structure.The unique functions of the bones and muscles in the goat limb in terms of cushioning and vibration damping were realized by using rods and springs.The static analysis showed that the proposed bionic device had good nonlinear positive stiffness and large working stroke.Based on the established dynamics model and using simulation methods,the effects of the design parameters on the damping effect of the large-stroke bionic nonlinear vibration isolation device were analyzed.The resonant frequency of the large-stroke bionic nonlinear vibration isolator was 2.1 Hz,and when the external vibration frequency was above 4.2 Hz,the bionic vibration isolator started to play a vibration suppression role.The bionic device adopted a unique bionic design,which could flexibly adjust the stiffness characteristics of the system by changing the design parameters of the device,and could achieve vibration isolation in a wide frequency range without active control,which provided a new idea for the design of bionic vibration isolation devices.5.A novel bionic limb vibration isolator with good load-bearing capacity for suppressing lowfrequency vibration was developed based on the design of goat hind limb structure.In this vibration isolator,long and short rods were used to imitate the long and short bones of goat hind limbs,and horizontally and tilted springs were used to imitate the muscles and tendons in multiple directions in the hind limbs.The static analysis revealed that the bionic limb isolator had good nonlinear stiffness and excellent load capacity,and its working range and load capacity could be flexibly adjusted according to the actual situation.The kinetic equations of the bionic vibration isolator were established,and the approximate solution of the equations was obtained by using the harmonic balance method.A prototype of the bionic device was fabricated to verify the rationality of the device design and vibration isolation performance.The experimental results showed that the bionic device could effectively isolate low-frequency periodic and random vibrations and exhibit good vibration isolation effect.When the vibration frequency exceeded 5 Hz,it could reduce the vibration excitation amplitude to more than 90%.The bionic device can effectively cope with complex and variable vibration excitation and has excellent low-frequency vibration suppression effect.