【作者】 范萍萍；

【导师】 李慧；

【作者基本信息】 兰州理工大学 ， 结构工程， 2010， 硕士

【摘要】 基础隔震技术作为一种有效的抗震设计手段在我国得到广泛的应用,为减轻地震灾害提供了一条合理、有效、安全的新途径,并在防震减灾事业中起到积极的推动作用。2008年汶川地震后,隔震结构在地震中表现出良好的抗震性能,使得隔震技术在我国得到了更加迅速的发展。针对隔震结构发展迅速且设计方法比较复杂这一现状,本文利用人工神经网络建立以隔震设计样本集为基础的因果关系网络,通过神经网络反映出上部结构基本参数与隔震后结构最大层剪力比和隔震支座最大位移之间较强的非线性关系,提出一种快速、高效的基于BP神经网络的基础隔震智能初步设计系统。首先,应用标准BP人工神经网络,以建筑结构的抗震设防类别、设防烈度、场地类别、地震分组、高宽比、长宽比、刚度,质量和面积为主要影响因子,以隔震后结构的最大层剪力比和支座最大位移为输出结果,建立隔震初步设计系统。通过网络测试表明该网络的准确率较高,说明基于标准BP神经网络的隔震初步设计系统对隔震结构减震效果的分析具有一定的可行性,但在网络的训练速度、精度等方面还有待进一步提高。其次,针对基于标准BP神经网络的基础隔震初步设计系统存在的问题,对标准BP神经网络进行改进,改进后的BP神经网络有效的提高了网络的学习速度,缩短了训练时间,提高了网络测试准确率。说明本文采用的改进方法是可行的,改进后的神经网络具有良好得推广价值和实际应用价值。最后,应用改进后的BP神经网络,结合隔震结结构设计的特点,建立了基础隔震智能设计系统。并利用MATLAB7.5强大的图形处理功能,设计了本系统的操作界面,使整个基础隔震智能初步设计系统具有良好的实用性和交互性。通过工程实例验证,本文建立的基础隔震智能初步设计系统操作简单、使用方便,能够将前人的设计经验通过神经网络储存并推广,为基础隔震设计起到辅助的作用。从而极大地提高工程设计的质量,缩短设计周期、加快设计进程,实现经验共享,提高整个隔震设计效率。更多还原

【Abstract】 As an efficient method of seismic design, base-isolation technology has been widely applied in our country, it provides a new approach reasonably which is effective and safe to the reduction of earthquake disasters and plays an active driving role in the works of earthquake administration. After Wen-chuan earthquake in 2008, base-isolation structure had good seismic performance in this earthquake, it more rapidly develop in our country.Aiming at the present situation of rapidly develop of base-isolation structure and complex design method, using artificial neural network established causality network based on base-isolation design samples, reflects nonlinear relation between basic parameters of superstructure and the maximum shear force ratio and the largest displacement of isolation bearing, the paper proposed a kind of rapid and efficient base-isolation intelligent initial design system based on BP neural network.First, using standard BP neural network, considering the seismic fortification type, fortification intensity, site type, seismic design group, height-width ratio, aspect ratio, stiffness, mass and area of structure as main impact factor, as the maximum shear force ratio and the largest displacement of isolation bearing to output data, this article sets up a base isolation structural initial design system. It shows that high accuracy by network tested and indicates that the analysis of vibration-isolating effect in base-isolation structure by base-isolation initial design system based on standard BP neural network has certain feasibility, but training speed and accuracy of network should be further improved.Second, aiming at the existing problems of base-isolation initial design system based on standard BP neural network, this paper discusses the existing defects of standard BP neural network and improves of these defects. Improved neural network improves the learning speed and the prediction accuracy, reduces the training time of the network. These indicate that the improved method is feasible and the improved BP neural network has a good application and promotional value.Finally, applying the improved BP neural network, and combined with the characteristics of base-isolation design, base-isolation intelligent initial design system can be established and graphical user interface can be make by MATLAB7.5 programming, which will make the system better practicality and interaction.Through the engineering practice, the base-isolation intelligent initial design system in this paper is simple to operate and easy to use and could store and extend previous experience as an auxiliary function for base-isolation design. Thus it can improve the quality of engineering design greatly, shorten design period, quickening design process, sharing experiences and improve design efficiency.更多还原