典型开合屋盖积雪分布规律研究

发布时间：2018-10-10 19:51

【摘要】：目前,国内外对开合屋盖结构设计的系统研究仍不完善,为促进开合屋盖结构快速发展,我国正在编制《开合屋盖结构设计规程》,其中在抗雪设计方面,开合屋盖因存在多个状态以及运行问题,较常规结构有更多要求。本文利用风致雪漂移试验及数值模拟方法研究三种典型刚性开合屋盖的积雪分布规律;最后利用ABAQUS有限元软件模拟积雪滑落的冲击效应。主要工作和结论包括以下几个方面:(1)确定了基于FLUENT的风致雪漂移数值方法。在是否考虑积雪面的反馈作用的对比中发现采用风雪单向耦合的稳态方法能较好地反映出发生积雪沉积或侵蚀的峰值位置及大小。采用标准k-ε模型更好地反应风雪流的湍流情况,并通过与实测值的对比验证了数值方法的可行性。(2)基于跃移层无量纲体积传输率一致的相似准则,采用风雪联合试验装置对水平移动开合屋盖进行风致雪漂移试验,模拟介质为人造雪,分析了不同开启状态、风速、风向角下的屋面雪深分布特征。与数值模拟结果对比发现:积雪发生沉积的范围存在差异,但积雪分布形式满足相同规律。(3)利用数值模拟方法研究三种开合屋盖形式在不同开启状态、风速、风向角下的屋面分布特征,探讨了矢跨比和屋盖突起高度对积雪分布的影响,并参照现有规范提出其积雪分布建议。研究表明屋盖高度对积雪分布的影响仅局限于局部区域;矢跨比直接影响屋盖形状,是影响积雪分布的关键因素。(4)基于Johnson-Cook本构和失效模型,采用ABAQUS有限元软件分析了屋面局部积雪滑落对挡雪栏杆的冲击效应。研究表明积雪滑落的冲击作用显著,挡雪栏杆受积雪滑落冲击时破坏模式为发生塑性弯曲变形;而带有挡雪夹的挡雪系统对抵抗大体积积雪滑落的能力差,通过分析总结对雪夹构造及布置形式提出了改进建议。
[Abstract]:At present, the systematic research on the structural design of the open and closed roof is still imperfect. In order to promote the rapid development of the open and closed roof structure, our country is compiling the Design Specification of the Open and closed Roof structure, which is in the aspect of snow resistant design. The opening and closing roof has more requirements than the conventional structure due to the existence of multiple states and operation problems. In this paper, the snow cover distribution of three typical rigid open and close roofs is studied by wind induced snow drift test and numerical simulation. Finally, the impact effect of snow fall is simulated by ABAQUS finite element software. The main work and conclusions are as follows: (1) A numerical method of wind-induced snow drift based on FLUENT is established. It is found that the steady-state method of wind and snow one-way coupling can better reflect the peak position and magnitude of snow deposition or erosion in the comparison of whether or not the feedback action of snow cover surface is taken into account. The standard k- 蔚 model is used to better reflect the turbulent flow of the wind and snow flow, and the feasibility of the numerical method is verified by comparison with the measured values. (2) based on the similarity criterion of the dimensionless volume transfer rate of the jump layer, The wind-induced snow drift test of horizontal moving open and close roof was carried out by using a combined test device of snow and snow. The snow depth distribution characteristics of roof under different open state, wind speed and wind direction angle were analyzed in the simulated medium of artificial snow. Compared with the results of numerical simulation, it is found that there are differences in the range of snow deposition, but the distribution of snow cover satisfies the same law. (3) numerical simulation method is used to study the three open and closed roof forms in different open states and wind speed. The characteristics of roof distribution under wind direction angle are discussed. The effects of the rise-to-span ratio and the height of roof protuberance on the snow cover distribution are discussed, and suggestions for snow cover distribution are put forward with reference to the existing codes. The results show that the influence of roof height on snow cover distribution is limited to local area, and the ratio of rise-to-span directly affects the shape of the roof, which is the key factor affecting snow cover distribution. (4) based on Johnson-Cook constitutive model and failure model, ABAQUS finite element software is used to analyze the impact effect of local snow sliding on snow barrier railings. The results show that the impact of snow slide is obvious, the damage mode of snow barrier is plastic bending deformation, and the snow retaining system with snow clip has poor ability to resist large volume snow fall. By analyzing and summarizing the structure and arrangement of snow clip, some suggestions are put forward.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU312.1

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