生物组织冻结过程中的应力分析

为了预测生物组织低温保存过程中所受到的机械损伤 ,建立了一维球对称模型 ,模拟计算了降温过程相变界面随时间的移动 ,壁面温度随时间的变化 ;组织内温度分布不均引起的热应力随时间变化及其在壁面的分布。主要考虑了降温速率的影响 ,当降温速率低于某一值时 ,降温速率越高 ,组织内部所受热应力越大 ;降温速率超出这个值 ,组织内的热应力不再随降温速率变化

ANALYSIS ON THERMAL STRESS DURING CRYOPRESERVATION

The aim of this study was to predict the cryoinjury that was caused by thermal stresses during cryopreservation of living cells, tissues and organs. A thermal stress analysis model is developed for water freezing processes taking place inside a ball. The model allows us to predict the temperature field, moving phase interface location and the thermal stress distributions in the ice. A quick freezing process results in larger thermal stresses in the ice than a slow freezing process does within a certain level. Above this level, the freezing rate has no effect on the thermal stresses.