SRC框架-RC核心筒混合结构多目标抗震优化设计研究

发布时间：2018-05-14 19:47

本文选题：SRC框架-RC核心筒混合结构 + 失效模式　；参考：《西安建筑科技大学》2013年博士论文

【摘要】：SRC框架-RC核心筒混合结构是一种新型的结构体系，它以优良的抗震性能和耐久性而被广泛应用于高层和超高层建筑中。本文采用理论建模的研究手段，对SRC框架-RC核心筒混合结构各构件及整体结构进行系统的优化研究，具体研究内容如下： 1.将SRC框架梁的工程造价最小化和正截面抗弯承载力最大化定为优化目标，并对其进行无量纲化处理，使得多目标的优化问题转化为单目标优化问题，采用线性加权法构造评价函数，，通过调整加权系数来改变两个优化目标在优化中的重要程度。考虑到SRC构件的受力特性，在遗传算法(GA)的编码过程中应用层次分析法理论对各设计变量进行权重赋值，从而建立层次分析GA算法。综合考虑各种约束条件，运用层次分析GA算法实施SRC框架梁的优化设计，并通过优化设计实例证实文中所采用的优化方法和设计思路是有效、可行的。 2.将SRC框架柱的工程造价最小化和斜截面抗剪承载力最大化定为优化目标，并在理论建模过程中将粘结滑移试验所得的本构方程应用于数值模型。考虑到SRC构件的混凝土截面尺寸和内埋型钢截面尺寸为主要优化设计变量，首先运用优化准则法(OC)确定构件混凝土截面尺寸，以达显著缩小解空间的搜索范围并提高计算效率之目标，进而确定型钢截面尺寸、纵筋直径与数量等设计参数的取值范围。基于以上思路，在优化准则法中，根据最优性准则Kuhn-Tucker条件推导出SRC框架柱混凝土截面尺寸的迭代公式，并将其与层次分析遗传算法相结合，从而建立了层次分析OC-GA算法。综合考虑各种约束条件，运用层次分析OC-GA算法实施SRC框架柱的优化设计，优化设计实例表明文中所采用的优化方法是有效、可行的。 3.将SRC框架的工程造价及结构层间位移差最小定为优化目标，并根据SRC框架结构在不同受力阶段各类构件的受力特性，提出两阶段优化设计的思路：小震作用下，认为混凝土处于开裂的临近状态，假定钢材未发挥作用，仅有混凝土发挥作用，据此对结构构件的截面尺寸与混凝土用量进行优化；在中震及大震作用下，对满足结构性能要求的钢材用量进行优化。综合考虑各种约束条件，运用层次分析OC-GA算法实施SRC框架的抗震优化设计，并通过优化设计实例证实文中所采用的优化思路是有效、可行的。 4.以SRC框架-RC核心筒混合结构的失效模式为研究背景，通过引入损伤函数，将结构的工程造价和损伤量最小定为优化目标，并根据建筑结构“三水准”抗震设防的目标要求，以及结构在不同受力阶段各类构件的受力特点，提出三水准优化设计的方法：小震作用下，仅对RC剪力墙和SRC框架梁、柱构件的混凝土用量进行优化；中震作用下，框架与剪力墙处于协同工作状态，据此对整个结构满足层间位移差最小之目标的钢材用量进行优化；大震作用下，结构处于塑性状态，剪力墙基本退出工作，据此对满足结构损伤值最小之目标的钢材用量进行进一步的优化。从而将一个多目标优化问题转化为多个单目标优化问题求解。综合考虑各种约束条件，运用层次分析OC-GA算法实施SRC框架-RC核心筒混合结构失效模式三水准的优化设计。通过优化实例证实文中所采用的优化设计思路是有效、可行的。 5.基于投资-效益准则的全寿命优化理论，在结构最优设防烈度优化设计阶段引入分灾的概念设计，从而建立基于全寿命分灾优化设计的数学模型，并通过优化实例证实文中所采用的优化设计思路是有效、可行的；进而，按最优设防烈度进行优化设计阶段引入失效模式优化理论，建立基于失效模式的SRC框架-RC核心筒混合结构全寿命分灾优化设计的数学模型。
[Abstract]:The SRC frame -RC core tube mixed structure is a new type of structure system. It is widely used in high rise and super high rise buildings for its excellent seismic performance and durability. In this paper, the research method of theoretical modeling is adopted to optimize the system of the components and the whole structure of the mixed structure of the -RC core tube of the SRC frame, and the specific research contents are studied. As follows:
1. the minimization of the cost of the SRC frame beam and the maximum bending bearing capacity of the cross section are determined as the optimization goal, and the dimensionless treatment is carried out to make the optimization problem of the multi-objective transformation into a single objective optimization problem. The linear weighting method is used to construct the evaluation function, and the optimization of the two optimization targets is changed by adjusting the weighting coefficient. Taking into account the stress characteristics of SRC components, the analytic hierarchy process (AHP) theory is applied to the weight assignment of each design variable in the genetic algorithm (GA) coding process, thus the hierarchical analysis GA algorithm is established. The optimization design of the SRC frame beam is carried out by the analytic hierarchy process GA algorithm, and the design example is optimized by using the analytic hierarchy process (AHP) algorithm. It is proved that the optimization method and design idea adopted in this paper are effective and feasible.
2. the minimization of the construction cost and the maximum shear capacity of the oblique section of the SRC frame column is determined as the optimization goal. The constitutive equation obtained by the bond slip test is applied to the numerical model in the theoretical modeling process. Considering that the size of the concrete section of the SRC component and the embedded steel section length are the main optimal design variables, the first use of the optimization is to apply the optimal design variables. The size of the concrete section of the component is determined by OC, so as to reduce the search scope of the solution space and improve the calculation efficiency, and then determine the range of the design parameters, such as the size of the steel section, the diameter and the quantity of the longitudinal reinforcement. Based on the above thought, the SRC is derived according to the Kuhn-Tucker conditions of the optimality criterion. The iterative formula of the concrete section size of the frame column is combined with the analytic hierarchy process genetic algorithm (AHP), thus the analytic hierarchy process (OC-GA) algorithm is established. The optimization design of the SRC frame column is implemented by the comprehensive consideration of various constraints and the AHP OC-GA algorithm. The optimization method used in the design example table is effective and feasible.
3. according to the minimum displacement difference between the construction cost and the structure layer of the SRC frame as the optimization target, and according to the stress characteristics of the various components of the SRC frame structure at different stage of stress, the idea of the optimization design is put forward. Under the action of small earthquakes, it is considered that the concrete is in the near state of the cracking, assuming that the steel is not exerting its function and only the concrete is exerting. On the basis of this, the section size and the amount of concrete are optimized. Under the action of medium earthquake and large earthquake, the amount of steel which meets the requirements of structural performance is optimized. The seismic optimization design of the SRC frame is implemented by the analytic hierarchy process (OC-GA) algorithm. The optimization idea adopted is effective and feasible.
4. taking the failure mode of the SRC frame -RC core tube mixed structure as the research background, by introducing the damage function, the minimum construction cost and the minimum damage amount are determined as the optimization target, and according to the target requirements of the seismic fortification of the building structure "three level", and the structure's stress characteristics at different stages of the structure, the three water quasi optimum is put forward. Under the action of small earthquakes, only the concrete dosage of RC shear wall and SRC frame beam and column member is optimized. Under the action of medium earthquake, the frame and shear wall are in cooperative working state, and the steel quantity of the whole structure satisfying the minimum displacement difference between layers is optimized. Under the action of large earthquakes, the structure is in plastic state. The shear wall is basically withdrawn from the work, and then the steel consumption of the target which satisfies the minimum damage value of the structure is further optimized. Thus a multi objective optimization problem is transformed into multiple single objective optimization problems. A comprehensive consideration of various constraints and the application of the analytic hierarchy process (AHP) OC-GA algorithm to the failure of the SRC framework -RC core tube mixed structure failure are carried out. The optimized design of the model is verified by an example. The optimization design ideas adopted in this paper are effective and feasible.
5. based on the whole life optimization theory of the investment benefit criterion, the concept design of the disaster division is introduced in the optimal design phase of the structural fortification intensity, and the mathematical model based on the life span optimization design is established, and the optimization design idea is proved to be effective and feasible. In the optimization design stage, the failure mode optimization theory is introduced, and the mathematical model of the SRC framework -RC core tube mixed structure full life disaster reduction optimization design based on failure mode is established.

【学位授予单位】：西安建筑科技大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TU973.31

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