恐龙蛋壳在外力作用下的三维有限元分析及其意义

ANALYSIS OF THREE-DIMENSIONAL FINITE ELEMENT OF DINOSAUR EGGS IN EXTERNAL FORCE AND ITS SIGNIFICANCE

研究恐龙蛋壳在外力作用下的三维应力分布有助于了解恐龙蛋在自然埋藏下的破坏规律及其稳定性,大型通用有限元软件ANSYS为研究恐龙蛋壳的破坏规律提供了一种更为直观的方法。利用ANSYS有限元软件对产自山东莱阳的金刚口椭圆形蛋、广东南雄的瑶屯巨形蛋和粗皮巨形蛋,以及一窝未经描述过的发现于江西赣州的长形蛋科成员分别建立有限元模型,对其在50KPa均布荷载下的三维应力分布进行模拟计算,得出在外力作用下三维应力分布的精细化图像。结果表明最容易破坏区域位于蛋壳的钝端直径与尖端直径之间,且越靠近钝端直径越容易破坏,这与研究标本所观察到的破坏规律相一致,也与恐龙孵化出壳位置相吻合。钝端与尖端直径差别越大,两端的等效应力差别越明显,随着赤道半径与蛋壳厚度之比(R/h)的增大,蛋壳抵抗外部荷载的能力下降,蛋壳越容易破坏。

To find out the failure law of dinosaur eggs and its stability in natural burial,the investigation into the three-dimensional stress distribution of eggshells in the external force is a beneficial method. ANSYS,large general-purpose finite element software, makes the investigation intuitive.The finite element models have been set up separately for Ovaloolithus chinkangkouensis discovered in Laiyang,Shandong Province,Macroolithus yaotunensis and Macroolithus rugustus discovered in Nanhsiung,Guangdong Province,and a clutch of undescribed elongatoolithids discovered in Ganzhou,Jiangxi Province. The models were analogously computed for its threedimensional stress distribution under 50 KPa evenly distributed load.In consequence,the fine images of three-dimensional stress distribution in the external force have been drawn.The results show the most vulnerable area is between the diameters of blunt and sharp ends,and closer to the blunt one.This conclusion is consistent with the failure law presented in the referred specimens and the outlet position of dinosaur hatching from the egg.The equivalent-stress difference between the diameters of blunt and sharp ends is relative to the difference of the both diameters. With the increment of the ratio of the equatorial radius to shell thickness（R/h）,the ability of the eggshells to fight the external load decreases,resulting in vulnerable eggs.