Dynamic Mechanical Properties Analysis Of Pig’s Knee Articular Cartilage

In daily life, people use their knee joint frequently. So knee joint injury is extremely common in movement. Articular cartilage injury is a common orthopedic disease in the knee joint injury. It is difficult to repair by itself once damage, because the cartilage cells regeneration ability is very limited. Treatment of articular cartilage injury has become a hot topic for orthopedics physcicians at home and abroad. There are many treatments and alternative materials have been proposed. In order to compare the mechanical properties of cartilage before and after repair, it is inevitable to adopt the method of Hopkinson pressure bar to research its dynamic mechanical properties. And in order to study the mechanism of articular cartilage damage, we have make use of the mechanical properties of articular cartilage to create a finite model.In this paper, firstly we introduce the composition and the principle of traditional Hopkinson pressure bar. We improve the device on the basis of traditional bars, and then establish our experiment system according to the material we will test. We checked the experiment system strictly in order to prove the accuracy. The core content of this paper is to test the dynamic characteristics of knee joint cartilage. For the sake of accurate dynamic stress strain curve, the power supply of wheatstone bridge of transmission signal has been improved, so the weak transmission signal has been further enlarged. In order to ensure constant strain rate loading and the sample deformed under uniform stress, we use a pulse shaper to filter the high frequency component from high speed impact and at the same time reduce the loading rate to ensure uniform deformation. On the other hand, we use quartz crystal to check the stress equilibrium conditions at the two ends of the specimen. Finally, we get the dynamic stress strain curve of knee joint cartilage under three kinds of strain rate1800s-1,2700s-1,3500s-1...