Investigation of the damage caused by wire contact points and its influence on the safety of running high-strength ropes

钢丝接触点损伤及其对高强钢丝绳运行安全影响的调查

• 批准号: 454015252
• 负责人: Professor Dr.-Ing. Robert Schulz
• 金额: --
• 依托单位: Institut für Fördertechnik und Logistik (IFT)
• 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/454015252?language=en
• 关键词: Investigation; damage; caused; wire; contact

The objective of the research project is to contribute to the clarification of the cause of failure in dynamically loaded (running) wire ropes with different static wire strengths, with special focus on the influence of wire contact points and press ellipses.Currently, in rope technology for running ropes, the rope tension load in comparison with the nominal rope strength is regarded as significant for the fatigue behaviour. This leads to an incorrect estimation of service life, especially in the case of high-strength wire ropes, as shown by the literature and the results of our own preliminary investigations. The current prediction that higher wire strengths lead to an increased rope service life is wrong; in fact, the service life is reduced! This contradiction in the estimation of service life is presumed in the previous neglect of the different deformability of wires of different strengths.In preliminary investigations it could be shown for the individual rope wire that a strain-based consideration of service life can solve the existing problem and provide a reliable, safety-related design. Based on the preliminary tests, we assume that rope failure is also caused by exceeding a critical elongation in the rope wires. In the research project applied for, a new method for determining the formation of damage and rope failure is to be developed. For the development of the method, the approach already used in related sciences, namely that component failure is limited by a maximum tolerable plastic deformation, is to be used. This means that the plastic strain accumulated during component operation, including previous deformations, determines the damage development and finally the service life. The solution approach of the planned research project is that indications of the service life of ropes of different strengths can be obtained from their relative stress-strain curves in tensile tests until breakage. The aim is to prove the influence of the plastic deformation of wires of different strengths on the service life of a rope manufactured from them. Special attention is focused on the formation and effect of contact points and press ellipses on the fatigue behaviour of ropes. This novel research approach will be investigated and validated.

该研究项目的目的是有助于澄清不同静态钢丝强度的动态载荷（运行）钢丝绳的失效原因，特别关注钢丝接触点和压力椭圆的影响。目前，在运行钢丝绳的钢丝绳技术中，钢丝绳张力载荷与名义钢丝绳强度的比较被认为对疲劳行为具有重要意义。这会导致对使用寿命的错误估计，特别是在高强度钢丝绳的情况下，正如文献和我们自己的初步调查结果所示。目前的预测，更高的钢丝强度导致增加绳索的使用寿命是错误的;事实上，使用寿命减少！使用寿命估算中的这种矛盾是由于以前忽略了不同强度钢丝的不同变形能力而造成的。初步研究表明，对单个钢丝绳而言，基于应变的使用寿命考虑可以解决现有问题，并提供可靠的安全相关设计。根据初步试验，我们假设钢丝绳断裂也是由于钢丝绳超过临界伸长造成的。在申请的研究项目中，将开发一种确定损伤和绳索失效形成的新方法。对于该方法的发展，已经在相关科学中使用的方法，即组件故障是由最大容许塑性变形的限制，将被使用。这意味着部件运行期间积累的塑性应变，包括之前的变形，决定了损坏的发展，最终决定了使用寿命。计划中的研究项目的解决方法是，不同强度的绳索的使用寿命的指示可以从它们在拉伸试验中的相对应力-应变曲线中获得，直到断裂。目的是证明不同强度钢丝的塑性变形对由它们制成的绳索的使用寿命的影响。特别注意的是集中在形成和接触点和压力椭圆的疲劳性能的绳索的效果。这种新的研究方法将被调查和验证。