Computer simulations based on numerical methods applied to the equilibrium equations of Newtonian mechanics have significant impact in many industries, because they provide cheaper development of products. Using computer simulations, it is possible to investigate behavior of product parts and assemblies under different boundary conditions, loads and applied materials, which significantly reduces the number of real expensive experiments. A large number of simulations can be conducted in order to optimize the geometry, materials, product price, etc. or to confirm that the product satisfies technical and safety requirements. By discretization of equilibrium equations, it is possible to simulate only continuous models, i.e. models whose all parts are physically connected. But a problem that occurs very often is mechanical contact between two or more independent mechanical parts. In case the parts are not physically connected, it is necessary to provide an additional boundary condition using a contact algorithm so that the independent parts would be aware of each other. Because of that, the contact problem between deformable moving bodies is always an interesting topic in computational mechanics and mechanical engineering in general. The problem that initiated the development of the contact algorithm presented in this paper is the possibility of numerical simulation of mechanical tests performed during the development of medical stents with the aim to provide a look inside, to show the state of stress or strain in material of the stent.

During the implementation of the contact algorithm, two problems arise: 1. finding contact surfaces between different elastic bodies and 2. preventing the penetration of one body into another body by additional boundary condition. This paper presents the implementation of a contact algorithm by finding boundary surface nodes of a deformable body that have penetrated the boundary surface elements of another deformable bodies, and adding boundary conditions that reverse the penetrated nodes to the body boundary. The algorithm is implemented within the in-house software package for finite element analysis. The software is written in Fortran, which is another challenge, given that Fortran does not have as powerful geometry libraries as other modern programming languages do. The main reason for this was compatibility with existing finite element code and facilitated implementation of future parallelization with the aim of reducing computing time.

基于数值方法应用于牛顿力学平衡方程的计算机模拟在许多行业中都具有重大影响，因为它们提供了更便宜的产品开发机会。使用计算机仿真，可以研究产品零件和组件在不同的边界条件，载荷和施加的材料下的行为，从而显着减少了真正昂贵的实验次数。为了优化几何形状，材料，产品价格等，或者确认产品满足技术和安全要求，可以进行大量的模拟。通过平衡方程的离散化，可以只模拟连续模型，即所有零件都物理连接的模型。但是，经常发生的问题是两个或多个独立机械零件之间的机械接触。如果零件之间没有物理连接，则有必要使用接触算法提供额外的边界条件，以使独立零件相互了解。因此，通常在计算力学和机械工程中，可变形运动体之间的接触问题始终是一个有趣的话题。引发本文提出的接触算法发展的问题是在医学支架开发过程中进行机械测试的数值模拟的可能性，其目的是提供内部外观，以显示材料的应力或应变状态。支架。有必要使用接触算法提供附加的边界条件，以使独立的部分相互了解。因此，通常在计算力学和机械工程中，可变形运动体之间的接触问题始终是一个有趣的话题。引发本文提出的接触算法发展的问题是在医学支架开发过程中进行机械测试的数值模拟的可能性，其目的是提供内部外观，以显示材料的应力或应变状态。支架。有必要使用接触算法提供附加的边界条件，以使独立的部分相互了解。因此，通常在计算力学和机械工程中，可变形运动体之间的接触问题始终是一个有趣的话题。引发本文提出的接触算法发展的问题是在医学支架开发过程中进行机械测试的数值模拟的可能性，其目的是提供内部外观，以显示材料的应力或应变状态。支架。通常，可变形运动体之间的接触问题一直是计算力学和机械工程中一个有趣的话题。引发本文提出的接触算法发展的问题是在医学支架开发过程中进行机械测试的数值模拟的可能性，其目的是提供内部外观，以显示材料的应力或应变状态。支架。通常，可变形运动体之间的接触问题一直是计算力学和机械工程中一个有趣的话题。引发本文提出的接触算法发展的问题是在医学支架开发过程中进行机械测试的数值模拟的可能性，其目的是提供内部外观，以显示材料的应力或应变状态。支架。

在实施接触算法期间，出现两个问题：1.在不同弹性体之间找到接触面；以及2.通过附加边界条件防止一个体渗透到另一个体中。本文介绍了一种接触算法的实现方法，该方法通过查找已穿透另一个可变形体的边界面元素的可变形体的边界面节点，并添加将穿透的节点反向转换为体边界的边界条件来实现。该算法在内部软件包中实现，用于有限元分析。该软件是用Fortran编写的，这是另一个挑战，因为Fortran没有像其他现代编程语言一样强大的几何库。