García Páez J M, Carrera A, Jorge E, Millán I, Cordón A, Rocha A, Maestro M, Castillo-Olivares J L
Servicio de Cirugía Experimental, Clínica Puerta de Hierro, Madrid, Spain.
J Mater Sci Mater Med. 2007 May;18(5):715-24. doi: 10.1007/s10856-006-0009-x. Epub 2006 Nov 30.
We studied the changes in energy consumption of samples of calf pericardium, when joined or not joined by sutures and adhesives, by means of hysteretic cycles. Sixty-four samples were subsequently subjected to tensile stress until rupture. An overlapping suture sewn in the form of a rectangle presented an acceptable mean resistance to rupture of over 10 MPa, although lower than the mean values in an unsutured control series where the mean resistance surpassed 15 MPa. The contribution of an acrylic adhesive to the resistance to rupture was negligible. The sutured samples that were reinforced with adhesives and had not been subjected to hysteretic cycles prior to rupture showed an anisotropic behavior. This behavior appeared to be lost in all the samples that underwent hysteretic cycles. We found an inflection point in the stress/strain curve following the stepwise increase in the load, with a value greater than and proximate to the final load applied. This inflection should be analyzed by means of microscopy. Finally, the mathematical relationship between the energy consumed and the stress applied, the strain or deformation produced and the number of cycles of hysteresis to which the samples were subjected was established as the ultimate objective of this study. The bonding systems provoked a greater consumption of energy, with the greatest consumption corresponding to the first cycle in all the series assayed. An equation relating the energy consumption in a sample to the number of hysteretic cycles to which it was subjected was obtained. Its asymptote on the x-axis indicates the energy consumption for a theoretical number of cycles, making it possible to estimate the durability of the sample.
我们通过滞后循环研究了小牛心包样本在缝合或未缝合以及使用粘合剂情况下的能量消耗变化。随后对64个样本施加拉伸应力直至破裂。以矩形形式缝合的重叠缝线呈现出可接受的平均抗破裂强度，超过10兆帕，尽管低于未缝合对照组的平均值，该对照组的平均抗破裂强度超过15兆帕。丙烯酸粘合剂对抗破裂强度的贡献可忽略不计。在破裂前用粘合剂加固且未经历滞后循环的缝合样本表现出各向异性行为。在所有经历滞后循环的样本中，这种行为似乎消失了。在逐步增加载荷后，我们在应力/应变曲线上发现了一个拐点，其值大于且接近所施加的最终载荷。应通过显微镜分析这个拐点。最后，确定样本消耗的能量与所施加的应力、产生的应变或变形以及样本所经历的滞后循环次数之间的数学关系是本研究的最终目标。粘结系统引发了更大的能量消耗，在所有测试系列中，最大的能量消耗对应于第一个循环。得到了一个将样本中的能量消耗与其所经历的滞后循环次数相关联的方程。其在x轴上的渐近线表示理论循环次数下的能量消耗，从而能够估计样本的耐久性。
