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应用神经网络的结构优化设计原理,对空间桁架结构优化进行研究。利用神经网络的模拟退火算法对结构优化设计作了一些探讨。通过空间钢桁架结构的优化设计算例,验证了神经网络用于结构优化的有效性与准确性。 相似文献
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文章以某大跨悬挑工程为背景,对比分析了实腹工字钢钢梁体系、大跨平面圆管桁架体系、整体空间桁架体系等3种不同的大跨悬挑结构承重体系,最终选用整体空间桁架体系。系统阐述了其建筑造型特点及结构布置形式,并基于计算软件开展了受力性能计算分析。结果表明,整体空间桁架体系设置合理,在满足建筑功能造型的条件下,构件应力比均得到合理控制,结构安全冗余度较高。同时,结合建筑自身造型特点,重点介绍了本工程中应用的3种增强大跨悬挑结构抗倾覆性能的措施。文章对此类大跨悬挑结构提出的相关设计建议可供类似工程参考。 相似文献
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文章以实际工程为例,介绍了空间悬挑钢桁架的制作、安装工艺,强调钢结构工程施工单位和设计单位相结合的重要性。 相似文献
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进行了两个螺栓球节点网架结构在不同施工阶段的挠度和杆件应变测试。将挠度测试结果分解,非荷载直接作用下引起的挠度变化明显,主要反映了构件几何尺寸的加工精度对挠度的贡献;荷载标准值直接作用下的测试挠度值与设计值的差异,明显地表示构件之间的连接状况对挠度的影响,表明施工过程中的挠度限值应分解区别对待。应变测试与分析结果表明杆件的应力在平均水平上设计值与测试值相当,但一些杆件内力性质发生变化,且弯矩普遍存在。不同施工阶段的数值计算表明,结构变形和杆件内力均随施工过程而变,一些杆件甚至可能屈服。施工阶段的验算十分必要。在设计中分区考虑螺栓球节点网架杆件弯矩的平均水平,对杆件内力进行平均水平上的调整是可行的。 相似文献
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以城市构成要素分析了厦门海湾公园规划案例,探讨了厦门市西海岸的空间形态优化设计,研究了该规划对优化整合城市空间形态,加强城市空间连续性,形成滨海开放空间的必要性和途径,并进行概要分析和总结,以期对城市滨水区空间形态的优化实践有所裨益。 相似文献
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“监造检验”是受建设单位(业主)委托、平行于施工单位自己检验的一种新的质量检验型式.本介绍了螺栓球节点网架工程质量监造检验的主要内容和常见问题的处理.正常情况下,网架工程的监造检验要分三次进行:第一次是网架主体零部件进场后、安装前,主要内容是施工图设计审查、主体零部件质量检验和基座预埋板位置复查;第二次是主体安装工程完成后、屋面工程开始前,主要内容是安装质量的目视普查、支座球高差测量和网架自重情况下的挠度测量;第三次是屋面工程完工后,主要内容是全部恒载状态下的网架挠度测量.章重点叙述了各个监造检验环节的必要性和常见问题的处理方法,结合《钢结构工程施工质量验收规范》GB50205—2001和《网架结构工程检验评定标准》JGJ78—91相应条款提出了自己的意见. 相似文献
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单次张拉预应力空间立体钢桁架的归并优化设计 总被引:1,自引:0,他引:1
基于拉索式空间预应力钢结构优化分析的计算方法,进一步得到了张拉预应力空间钢桁架归并优化计算模型.利用该模型可根据实际设计需要对索张拉空间预应力钢结构单元进行任意的归并优化.本文利用所建立的优化方法对工程中有应用前景的三角立体钢桁架结构进行了优化分析,并讨论了不同参数变化对优化结果的影响,同时结合相应非预应力结构的优化结果进行了对比分析。为工程应用提供了一定的参考依据. 相似文献
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在正放四角锥网架结构抗火性能研究基础上,进一步分析两向正交正放网架、正放抽空四角锥网架和斜放四角锥网架在大空间建筑火灾中的热力耦合反应.基于有限元程序ANSYS建立网架结构上弦压杆应力比一致的结构分析模型,按温度增量加载的方法对网架结构热力耦合非线性反应进行了分析.结果表明,在大空间建筑火灾非均匀温度场中网架结构具有不同的杆件失效路径,正放四角锥网架、正放抽空四角锥网架和斜放四角锥网架在各自的杆件失效路径下临界温度趋于一致;网架结构在火灾中产生适度数量的杆件破坏,可更大程度地释放附加温度应力,表现出结构具有较高的抗火承载力和临界温度;两向正交正放网架的水平支撑桁架体系的抗火承载力对结构的整体抗火承载力有较大影响.按上弦杆具有相同应力比的结构模型,分析得到的失效杆件是影响结构抗火承载力的关键杆件.上述结论可为进一步研究网架结构抗火设计方法提供理论依据. 相似文献
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Luciano Mendes Bezerra Cleirton Andr Silva de Freitas William Taylor Matias Yosiaki Nagato 《Journal of Constructional Steel Research》2009,65(12):2197-2206
Steel space trusses are generally made of tubular section members. There are several types of links to connect these members. The most popular is the end-flattened connection. The advantages of such connections are reduced costs and fast assemblage of the truss. However, they present disadvantages such as eccentricities and stiffness reduction of members. In this work, based on computer simulations and nine experimental lab tests on space truss prototypes, small changes on the end-flattened connections such as reinforcement and eccentricity correction are evaluated. The results show a 68% increase for local collapse and a 17% increase for global collapse in the truss load carrying capacity. Global and local collapses are, respectively, associated with the ultimate limit state and serviceability limit state. 相似文献
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The present paper deals with the weight minimization of tubular trusses subjected to multiple loads under size, stress and buckling constraints. The applied optimization procedure is based on a virtual strain energy density approach developed by the first two authors, already tested in plane and space truss structures. The key point of the method is the activation of at least one of the imposed displacement constraints. In case where such limitations are absent, a dummy displacement constraint is introduced instead, which iteratively sustains corrections until convergence is achieved within the desirable tolerance. The efficiency and practicability of the proposed method was tested in typical cases of tubular truss structures. For reasons of comparison, the same cases were also optimized using Sequential Quadratic Programming (SQP), which is a powerful mathematical programming optimization method. The results revealed that the proposed method performs very well in terms of convergence, of required number of iterations and of optimum tracing, while the value of the introduced dummy displacement constraint has insignificant effect on the optimization procedure. 相似文献
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结合通用有限元软件ANSYS的有限元分析和APDL语言建立了网架结构的参数化模型,介绍了网架结构优化设计的基本过程,并以周边简支的正四角锥网架为例进行了结构优化分析,分析结果验证了ANSYS在网架结构优化中的可行性。 相似文献
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This paper deals with the weight minimization of planar steel trusses by adopting a differential evolution-based algorithm. Square hollow sections are considered. The design optimization refers to size, shape and topology. The design variables are represented by the geometrical dimensions of the cross sections of the different components of the truss, directly involving the size of the structure, and by some geometrical parameters affecting the outer shape of the truss. The topology is included in the optimization search in a particular way, since the designer at different runs of the algorithm can change the number of bays keeping constant the total length of the truss, to successively choose the best optimal solution. The minimum weight optimum design is posed as a single-objective optimization problem subject to constraints formulated in accordance with the current Eurocode 3. The optimal solution is obtained by a Differential Evolutionary (DE) algorithm. In the DE algorithm, a particular combination of mutation and crossover operators is adopted in order to achieve the best solutions and a specific way for dealing with constraints is introduced. The effectiveness of the proposed approach is shown with reference to two case-studies. The analysis results prove the versatility of the optimizer algorithm with regard to the three optimization categories of sizing, shape, topology as well as its high computational performances and its efficacy for practical applications. In particular useful practical indications concerning the geometrical dimensions of the various involved structural elements can be deduced by the optimal solutions: in a truss girder the cross section of the top chord should be bigger than the one of the bottom chord as well as diagonals should be characterized by smaller cross sections with respect to the top and bottom chords in order to simultaneously optimize the weight and ensure an optimal structural behaviour. 相似文献