Abstract The paper presents the method of modeling the elastic deformations of expanded graphite, a material used as flexible filling in spiral wound gaskets. Five methods (from A to E) were proposed, by means of which the mean values of the effective elasticmodulus were determined on the basis of the experimentally determined stress-strain characteristics of expanded graphite. The values determined in this way constituted the data set into the isotropic material model, reflecting the elastic properties of the expanded graphite tape in the numerical spiral wound gasket model. A different way of modeling the graphite's elastic properties using the numerical model was method F, in which a nonlinear hyperelastic material model proposed by Blatz-Ko was adapted. The basic purpose of the numerical calculations was to determine both the compression curve of the gasket and the stress distribution in the gasket's windings. The obtained numerical results of the gasket's compression were compared with the experimental test, which allowed the assumptions of the numerical models to be validated. The best way to reflect the elastic behavior of expanded graphite in the gasket's numerical model turned out to be the nonlinear material model presented in method F.

中文翻译：

---

压缩膨胀石墨的弹性特性建模 - 一种用于缠绕垫片的材料

摘要 本文介绍了对膨胀石墨的弹性变形进行建模的方法，膨胀石墨是一种用作螺旋缠绕垫片中的柔性填充物的材料。提出了五种方法（从 A 到 E），通过这些方法，根据实验确定的膨胀石墨应力应变特性确定有效弹性模量的平均值。以这种方式确定的值构成了各向同性材料模型中的数据集，反映了数值螺旋缠绕垫片模型中膨胀石墨带的弹性特性。使用数值模型模拟石墨弹性特性的另一种方法是方法 F，其中采用了 Blatz-Ko 提出的非线性超弹性材料模型。数值计算的基本目的是确定垫圈的压缩曲线和垫圈绕组中的应力分布。将获得的垫圈压缩的数值结果与实验测试进行了比较，从而验证了数值模型的假设。在垫片的数值模型中反映膨胀石墨的弹性行为的最佳方式是方法 F 中提出的非线性材料模型。