基于弹性模量调整法的钢岔管结构设计与优化

The steel branch pipe (SBP) can be recognized as the "throat" of a penstock system, whose failure may induce heavy casualties and property losses. For having complicated configurations, the SBP has been designed by coarse analytical method preventing against strength failure. The design method does not introduce those advanced structural analysis methods, and does not meet those practices from preventing against shakedown failure and fatigue failure. In addition, the scheme selection method, usually used for the optimization of the SBP, is not based on rigorous mechanical and mathematical theories. The structural scheme optimized is strongly influenced by the experience of designer. Therefore, it is necessary to research on the theory and method of design and optimization for the SBP. In this proposal, model test, analytical theory and numerical simulation will be combined used. The damage mechanism of the SBP will be discovered, and its calculation model for structural analysis will be established. An elastic modulus adjustment method for calculating safety indices of preventing strength, shakedown and fatigue failure, will be presented based on the generalized mechanical and mathematical theories. The criterions for safety indices and the limit state equations will be determined. The design method by analysis for the SBP will be founded. Based on the design method, identification technique of high-stressed region, adjustment strategy of sectional strength and optimization convergence criterion will be found, and an elastic modulus adjustment procedure based design and optimization method by structural analysis for the SBP will be then proposed, which can be used as a new scientific theory and method for design and optimization of penstocks.

钢岔管常被视为水电站引水系统的"咽喉"，发生破坏将造成不可估量的生命和财产损失，然而由于体形和结构复杂，其结构设计长期依据仅考虑抵抗强度破坏的较粗糙的解析方法进行，既未引入已长足发展的结构分析方法，也未纳入工程实际中需考虑的抵抗安定破坏和疲劳破坏内容，且其结构优化主流方法-方案比选法缺乏严格的力学和数学理论依据，受限于设计者的已有经验，因而开展钢岔管设计与优化方法研究是必要的。 本项目拟结合模型试验、理论分析和数值模拟方法,揭示钢岔管结构的损伤破坏机理，建立其结构分析计算模型，提出基于统一力学和数学理论的强度、安定性和疲劳安全评价指标求解的弹性模量调整法，确定评价指标控制标准和极限状态方程，提出钢岔管的分析设计法，同时建立基于分析设计的结构高承载区识别方法、截面强度调整策略和优化收敛准则，形成可配套应用的基于弹性模量调整法的钢岔管设计与优化方法，为管道设计与优化提供新的科学理论与方法。

钢岔管常被视为水电站引水系统的“咽喉”，发生破坏将造成不可估量的生命和财产损失，然而由于体形和结构复杂，其结构设计长期依据仅考虑抵抗强度破坏的较粗糙的解析方法进行，既未引入已长足发展的结构分析方法，也未纳入工程实际中需考虑的抵抗安定破坏和疲劳破坏内容，且其结构优化主流方法—方案比选法缺乏严格的数学和力学理论依据，受限于设计者的已有经验，因而开展钢岔管设计理论与方法研究是必要的。.本项目结合模型试验、理论分析和数值模拟方法,揭示了钢岔管结构的损伤破坏机理，建立了其结构分析计算模型，提出了基于统一力学和数学基础的强度、安定性和疲劳安全评价指标分析的弹性模量调整法，确定了评价指标控制标准和极限状态方程，提出了钢岔管的分析设计方法，同时建立了基于分析设计的结构高承载区识别方法、截面强度优化调整策略和优化收敛准则，形成了可配套应用的基于弹性模量调整法的钢岔管分析设计与优化方法，为管道设计与优化提供了新理论。