摘要
为了预测血管组织低温保存过程中所受到的机械损伤，本文建立了一维对称具有同心孔的圆筒模型，模拟计算了降温过程壁面温度随时间的变化；冻结过程中体积膨胀和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．本文计算了热应力在径向、周向和轴向的分布，径向应力小于周向应力和轴向应力；由相变引起的应力大于由温度分布不均引起的应力；主要考虑了降温速率的影响，降温速率越高，组织内部所受热应力越大；当降温速率是１Ｋ／ｍｉｎ时最大周向应力为０．１２Ｍｐａ，降温速率为１２Ｋ／ｍｉｎ时最大周向应力为０．６Ｍｐａ；当热应力超过血管组织所能承受的极限值时，在血管壁上会产生裂纹；使组织受到损伤。
The aim of this study is to predict the cryoinjury that is caused by thermal stresses during cryopreservation of living cells, tissues and organs. A thermal stress analysis model is developed for water freezing process taking place inside acolumn. The model allows us to predict the temperature field and the thermal stress distributions in the ice. The maximum tensile stress occurs during phase change. The radial stresses are less than the circumferential stresses and axial stresses. A quick freeing process results in larger thermal stresses in the ice than a slow freeing process does. When the cooling rate is IK/min the maximal stress is 0.12Mpa; when the cooling rate is 12K/min the maximal stress is 0.6Mpa. If the maximum tensile stress exceeds the failure strength, the crack will initiate on the wall of blood vessel.
出处
《医用生物力学》
CAS
CSCD
2000年第1期13-18,共6页
Journal of Medical Biomechanics
基金
国家自然科学基金!(59836240)
