Continuum-based design of selectively compliant mechanisms taking into account large deformations

考虑大变形的选择性柔顺机构的基于连续体的设计

• 批准号: 398231358
• 负责人: Professor Dr. Alexander Hasse
• 金额: --
• 依托单位: Professur Maschinenelemente und Produktentwicklung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/398231358?language=en
• 关键词: Continuum; based; design; selectively; compliant

Conventional mechanisms generate the deformations necessary to perform their task through relative motions of components sliding or rolling on each other. Compliant mechanisms, on the other hand, use elastic strain, which leads to many advantages. The complexity in the mathematical formulation that arises directly from the operating principle of compliant mechanisms has hindered progress in the field to date. In conventional mechanisms, there is a clear separation between functional (desired) and undesired deformations based on the underlying physical principle. In compliant mechanisms, both desired and undesired deformations are based on elastic strain and an option for mathematical modeling, which only considers the desired part, is not available. For this reason, the synthesis of compliant mechanisms turns out to be very complex.One possible way for synthesis are continuum-based synthesis methods. Here, the mechanism is modeled as an elastic continuum and the geometry of the mechanism is freely adjustable. Currently, there are numerous continuum-based synthesis approaches, but they have some central shortcomings. Most synthesis approaches are only suitable for relatively simple tasks, while complex tasks such as shape adaptation are rarely covered. Moreover, only a limited range of transverse loads is considered in these approaches.With the idea of making the eigenproperties of the mechanism the subject of the synthesis (modal procedure), the applicant proposed a promising way to address these two shortcomings. The central advantage of this idea is the possibility of a kinematic design, i.e. a design that does not refer to specific load cases. This is otherwise only possible for conventional mechanisms, as well as with certain methods for designing compliant mechanisms (pseudo-rigid body approach), for which, however, the choice of the geometry of the mechanism is severely limited.In the course of the previous project , a new approach was elaborated that made the already existing procedures more robust. In addition, the modal procedure was extended to the case of the synthesis of mechanisms with multiple pseudo-mobility. The pseudo-mobility defines the number of scalar parameters needed to identify a single desired deformation of a compliant mechanism and can be related to the mobility of conventional mechanisms. However, the validity of the developed approach has so far been limited to geometrically linear mechanisms. The present application aims to extend it to the geometrically nonlinear case. This extension will provide a powerful tool that allows for the synthesis of complex compliant mechanisms with large deformations.

传统的机构通过部件在彼此上滑动或滚动的相对运动来产生执行其任务所需的变形。另一方面，柔顺机构使用弹性应变，这导致许多优点。从柔顺机构的操作原理直接产生的数学公式的复杂性阻碍了迄今为止在该领域的进展。在传统机构中，基于基本的物理原理，在功能性（期望的）变形和不期望的变形之间存在明确的分离。在柔顺机构中，期望的和不期望的变形都基于弹性应变，并且数学建模的选项（其仅考虑期望的部分）不可用。基于连续体的柔性机构综合方法是柔性机构综合的一种可能途径。在这里，该机构被建模为弹性连续体和机构的几何形状是自由可调的。目前，有许多基于连续统的合成方法，但它们有一些核心的缺点。大多数合成方法只适用于相对简单的任务，而复杂的任务，如形状适应很少覆盖。此外，在这些方法中仅考虑有限范围的横向载荷。由于将机构的本征特性作为综合（模态过程）的主题，申请人提出了一种有希望的方法来解决这两个缺点。这个想法的主要优点是运动设计的可能性，即不涉及特定载荷情况的设计。这是唯一可能的，否则传统的机制，以及与某些方法设计的顺应性机制（伪刚体的方法），其中，然而，选择的几何形状的机制是严重限制。在以前的项目过程中，一个新的方法进行了详细说明，使现有的程序更强大。此外，将模态方法推广到具有多个伪自由度的机构综合问题。伪移动性定义了识别柔顺机构的单个期望变形所需的标量参数的数量，并且可以与常规机构的移动性相关。然而，到目前为止，所开发的方法的有效性仅限于几何线性机制。本申请旨在将其扩展到几何非线性情况。这种扩展将提供一个强大的工具，允许合成复杂的顺应性机构与大变形。