由于其负泊松比、负热膨胀系数等特殊性能，具有可设计性的折纸结构，在近些年来应用越来越广泛。针对折纸结构的研究中，力学性能是非常重要的一个部分。 折纸结构由折痕和壳组成。折痕张角的变化、壳的弯曲导致了折纸结构的整体变形。现有研究中，为简化起见，多数分别考虑折痕和壳对变形的贡献。而实际变形中，两种变形模式是耦合的。本文研究了折痕和壳的耦合效应，并且给出了一种求解折纸结构变形的简化方法。主要研究成果如下： 用解析的方法，求解了带折痕的壳受拉伸问题。将折痕作为边界条件，求解壳的大变形微分方程，并给出了耦合方程组的数值解。发现折痕刚度、壳的尺寸会显著影响两种变形机制（折痕张角，壳弯曲）对于整体变形的贡献比例，并给出了必须考虑二者耦合效应的范围。考虑到解析分析此简单问题的求解难度，对于更复杂的结构必须采用简化的求解方案。 基于实验和理论分析，给出了折痕的等效刚度。考虑了壳和折痕的耦合效应，在计算折痕等效刚度时加入壳弯曲的影响。另外，提出了利用虚拟折痕来表征壳变形的思想。在简单变形下，令虚拟折痕的势能与壳的弯曲变形能相等，可以得到虚拟折痕的刚度（量纲为壳的弯曲刚度对宽度之比），这两个刚度的比值可以作为折纸结构变形算法选择的判据。 提出了一种求解折纸结构变形的简化方法——虚拟折痕法。利用真实折痕和虚拟折痕的角度变化模拟整个折纸结构的变形，真实变形对应折痕整体势能的最小值。此外，将虚拟折痕法用于分析壳的大变形、以及折痕壳的双稳态问题，都获得了很好的效果。 该工作从实验和理论出发，初步建立了一套求解折纸结构变形的方法。

With the novel properties such as negative Poisson’s ratio, negative thermal expansion coefficient, the Origami structures that have a good design ability have been widely used in various areas. While studying Origami structures, their mechanical response is one of the most important concerns. Origami structures consist of creases and shells. To simplify the problem, most existing papers studying the mechanical responses of Origami structures only consider one of the two factors. However, in many cases, both two deformation modes happen in the meantime and they are coupled together. So, the coupling effect of creases and shells is systematically studied in this paper. And a simulation method called virtual crease method is developed in this paper to get the deformation of Origami structures. The main outcomes of this work are list below: An analytical method is proposed while solving the tension of the creased shell. In this problem, the effect of ceases is shown in the boundary of the governing equations. The numerical result of this problem is given. The result shows that the stiffness of creases and the size of the creased shell will affect the contribution of the two deformation modes (the rotation of creases, the bending of shells). A region that both two deformation modes should be considered is given. Considering the difficulty of solving this simple problem, a simplified method should be given to solve more complicated problems. Besides, a method that combines experiments and analytic is proposed in this work. This method can take the bending of shells into consideration while obtaining the stiffness of real creases. Also, a method to get the stiffness of virtual creases is proposed. In this method, the bending energy of creases is equal to the potential energy of virtual creases in simple deformation and then get the stiffness of virtual creases (scales as bending stiffness over the width of the creased shell). This conclusion is very important for complicated Origami structures while choosing the suitable algorithm. A simplified method to solve the deformation of Origami structures-virtual crease method is given. Its basic idea is to model the deformation of Origami structures as the rotation of many virtual creases and real creases. The solution of this method is the extreme point of the strain energy. Besides, virtual crease method has been used to solve the large deformation of shells and the bi-stability of Origami structures. The results of this method fit with the experimental result in these problems. Based on theoretical analysis and experiments, this work has developed the framework of the virtual crease method.