Research On Biomechanical Model Of Human Knee Joint Based On ANSYS

As the irregular geometric shape and the non-uniform composition of the material at the Knee Joint, it is impossible to do the mechanical testing on the human body. So in recent years, Medical Imaging methods, Computer Imaging processing, 3D Modeling, and Finite Element Analysis (FEA) methods become the effective means to understanding of the human body, which are received increasing attention in the Knee Joint biomechanics research. The task of this paper is to generate geometry models of Knee Joint from high resolution medical images and to bring them into FEA software for mechanical analysis.In the aspect of 3D geometric modeling, this paper emphasized on the construction of the whole processing produce of establishing 3D geometry model of Knee Joint based on the 1mm thickness of CT slice medical images, including Medical Imaging methods, Computer Image processes and 3D modeling methods. Then using of the medical reconstruction software Mimics to establish the total Knee Joint and tibia fracture model. The shape of the modeling accords with their status in vivo and express anatomical characters in detail.In the aspect of FEA, ANSYS software is used to carry out a series of simulation studies on the tibia model in this paper, which is a body weight of 70Kg at standing position with boundary constraints and loads. As the bones are non-uniform and anisotropic composite materials, we use the method of converting the gray value of images to assign different material properties respectively on compact bone, cancellous bone and medulla, which make the computational model more accurate.The results from the simulation display that the maximum displacement collapse achieves 9.647mm on the lateral tibia platform, the maximum SEQV and shear stress at xy directions distribute on the outer platform. Compared with relevant clinical knowledge and previous'research results, it is match the actual situation of tibia stress. So the tibia model is scientific and effective.In general, a system of research technique is established in this paper, which combines Computer Tomography (CT), methods of image processing, 3D reconstruction and FEA, to discuss the whole process of segmenting original images, reconstructing the model of Knee Joint, which is introduced into FEA software and then simulating the force of knee fracture. 3D reconstruction and FEA are applled and expanded on the solid mechanics in biological research base on image data.