不同加载条件下的腰椎间盘蠕变实验研究

Creep experiments study on lumbar intervertebral disc under different loading conditions

为研究加载条件对腰椎间盘蠕变性能的影响,以新鲜猪腰椎间盘为研究对象,采用非接触式数字图像相关技术,考虑不同压缩应力及加载速率,对椎间盘进行蠕变实验,并建立蠕变本构模型。结果表明:施加压缩应力时,椎间盘蠕变曲线呈指数规律变化;相同加载速率下,蠕变应变随着应力的增大而增大;应力相同时,加载速率越大,蠕变应变越小;利用三参数粘弹模型建立的椎间盘本构方程与实验结果具有较好的相关性,该能够预测椎间盘的蠕变性能。研究结果为临床进一步研究人体椎间盘粘弹特性提供理论基础。

In order to study the effects of loading conditions on the creep properties of lumbar disc, considering different compression stress and loading rate, creep experiments with fresh porcine lumbar intervertebral disc were implemented by an optimized digital image correlation （DIC） technique. The creep constitutive model was established. The results show that creep curves of the intervertebral disc showed exponential rule change under the compression stress; creep strain increased with the increase of stress as the same loading rate; the larger the loading rate, the smaller the creep strain under the same stress. The constitutive equation of intervertebral disc established by using three-parameter viscoelastic model had good correlation with the experimental results. It can predict the creep properties of intervertebral disc. The research results provide a theoretical basis for further study of viscoelastic properties of human intervertebral disc in clinical.