Probabilistic concept for deformation-based design of hybrid elements like composite beams

基于变形的混合元件（如组合梁）设计的概率概念

• 批准号: 236662333
• 负责人: Professor Dr.-Ing. Karsten Geißler
• 金额: --
• 依托单位: Fachgebiet Stahlbau
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/236662333?language=en
• 关键词: Probabilistic; concept; deformation; based; design

The design method for composite members is based on the semiprobabilistic safety concept. The safety factors for resistance are based on the characteristic behavior and the statistical spread of materials. But, depending on material combinations and ductility of joints, for a specific composite member it can be necessary to use different safety factors with other weighting of the influences. From a scientific point of view, a simple transformation of safety factors based only on the behavior of the material or of the composite joint is not correct. In order to realize the required safety level a generalizable safety concept has to be developed for composite members.The basic principles of this safety concept will be developed using the example of the well known composite beams. Out of existing and new composite beam tests the statistic spread of load-deformation-behaviour will be determined at different states. Additional FEM analysis will enlarge the number of available data by parametric studies. The behavior of composite beams will be evaluated at serviceability limit state and at ultimate limit state using the reliability theory. Evaluation will be done at the level of cross section performance taking into account the slip in the composite joint and its statistical spread.Systematic calculation using reliability method will lead to a weighting of the relevant input parameters in ultimate limit state. So the necessary partial safety factors for resistance can be justified. The behavior of composite beams at serviceability limit state will be evaluated on basis of deformations. In this process slip in the composite joint will be taken into account. The exceeding of deformation limits will be a new failure criterion in the probabilistic evaluation of the beam behavior. This leeds to a new approach in the design method for composite beams that is necessary to guarantee the required safety level.Finally the new concept for the justification of safety factors will be generalized so that it can be applied for different types of composite members.

复合构件的设计方法基于半生产的安全概念。阻力的安全因子基于特征行为和材料的统计扩展。但是，根据关节的材料组合和延展性，对于特定的复合构件，有必要将不同的安全因子与其他影响的其他权重使用。从科学的角度来看，仅基于材料或复合关节行为的安全因子的简单转换是不正确的。为了实现所需的安全级别，必须为复合成员开发可推广的安全概念。该安全概念的基本原理将以众所周知的复合梁的示例来开发。在现有和新的复合梁测试中，将在不同状态确定负载变形的统计扩展。其他FEM分析将通过参数研究扩大可用数据的数量。使用可靠性理论，将在可使用的极限状态和最终极限状态下评估复合梁的行为。评估将在复合关节中的滑移及其统计扩展中的横截面性能级别进行。使用可靠性方法的系统计算将导致在最终极限状态下相关输入参数的加权。因此，可以证明必要的抵抗局部安全因素是合理的。将根据变形评估复合梁在可维护性极限状态下的行为。在此过程中，将考虑复合关节中的单位。超过变形极限将是对梁行为的概率评估中的新故障标准。这是为了保证所需的安全水平所必需的设计方法中一种新方法的LEED。在本文中，将概括安全因子的正当理由，以便将其应用于不同类型的复合构件。