An impact sensitivity assessment method of spacecraft based on virtual exterior wall

The impact sensitivity assessment of spacecraft is to obtain the probability of spacecraft encountering the OD/M(orbital debris or meteoroid),which is a prerequisite for survivability assessment of on-orbit spacecraft.An impact sensitivity assessment method of spacecraft based on virtual exterior wall was proposed to improve the computational efficiency.This method eliminates determination of the outermost surface elements of the spacecraft before generating the debris rays,which are assumed to originate from a non-concave virtual wall that completely wraps the spacecraft.The Dist Mesh method was adopted for the generating of the virtual wall to ensure its mesh quality.The influences of the sizes,mesh densities,shapes of the virtual wall on the efficiency and accuracy were considered to obtain the best combination of the size and mesh density of the wall and spacecraft.The results of this method were compared with those of S3DE(Survivability of Spacecraft in Space Debris Environment),BUMPER,MDPANTO,ESABASE2/Debris to verify the feasibility of the method.The PCHIP(Piecewise Cubic Hermite Interpolating Polynomial)was used to fit the size vs.flux relationship of the space debris to acquire the impact probability of OD/M with arbitrary size on the spacecraft.

The Theoretically Studies and Field Testing of Self-Insulation Exterior Wall in the Hot Summer and Cold Winter Zone

The energy efficiency design of the exterior wall in the buildings of the hot summer and cold winter zone of China should consider the heat prevention in summer and the heat insulation in winter. The self-insulation of the exterior?wall is a more feasible design to satisfy the energy efficiency of buildings in the?zone. However, the systematic research is urgently needed for the self-insulation of the exterior wall in the hot summer and cold winter zone of China. The paper tested the thermal performance of the common non-clay materials such as shale sintered hollow brick, sand autoclaved aerated concrete block, etc. by means of indoor experiments. The energy efficiency effect of the common materials was verified using dynamic calculation soft PKPM and several constitutions of exterior wall with different main bricks and insulation materials on the heat bridge were simulated, too. Besides, the tests of the thermal performance of exterior wall in real constructions were carried out to testify the practical effect of the recommended constitutions of exterior wall with different main bricks and insulation materials on the heat bridge. The conclusions are: the physical and thermal properties of the six non-clay wall material are better than the clay porous brick;the thermal performance of the non-clay brick can be improved obviously through the rational arrangement of the holes;shale sintered hollow brick after increasing the holes and rationalizing the hole arrangement and sand autoclaved aerated concrete block are recommended for buildings in the hot summer and cold winter area of China. The dynamic calculation results show that the thermal performances?of the non-clay materials are all satisfied with the energy efficiency;The heat transfer coefficient of the exterior wall with composition?③,?in which?the main wall was sand autoclaved aerated concrete block and the material on the heat bridge was sand autoclaved aerated concrete plate, is the smallest among the three recommended compositions.

Improvement of UAV Based an Evaluation Approach to Mid-High Rise Buildings'Exterior Walls

This research will develop a set of assessment techniques and proce-dures for exterior wall deterioration detection.The proposed method is mainly based on equipped with high-resolution photographic equipment for unmanned aerial vehicle(UAV).To overcome the problems of visual inspection difficulties due to diferent angles and height,the proposed method provides a safer and more efficient detection way to get the buildings'exterior status.After using the pro-posed method to analyze the images taken from UAV,the size of the damaged area can be evaluated more accurately,and the accuracy rate of visual assessment will be significantly improved.The results of the proposed method can reduce the accidents caused by the inspection process in the critical environment and the costs incured by the temporary facilities without sacrificing the quality of the inspection results.Then,the research will implement the existing visual assessment method because of the characteristics of rapid detection,however,the assessment results will be different from different inspectors due to subjectivity.Thus,the research will present an improved visual inspection method by using UAV and Forward Looking Infred Thermal technology (FLIR).The result will be presented by Condition Index(CI-Level)instead to improve the subjectivity of the personnel.

Present Situation and Problems Analysis of Waterproof and Seal of Prefabricated Building Exterior Wall

With the continuous development and progress of China's social economy,the construction speed of our construction industry is also accelerating.Compared with the traditional cast-in-place reinforced concrete and masonry building,it has been unable to meet the requirements of the construction industry and the development of the times.Because the prefabricated building has the advantages of fast speed,water saving,land saving,noise reduction,material saving and energy saving in installation.Compared with traditional buildings,the prefabricated building is more energy efficient and practical.Therefore,the new type of precast assembly architecture is constantly highlighted and has become the mainstream of the development of the future construction industry.However,the technology started late in China,and the immature technology and imperfect supporting standards led to slow progress and even stagnation in China's construction industry.Through the analysis of the present situation and problems of the waterproof and sealing of the prefabricated building exterior walls,the suggestions for the healthy development of the construction industry in China are put forward in time.

Research on Building Exterior Wall Decoration and Its Energy Saving Optimization

This paper mainly uses the method of numerical simulation, and study thermal insulation and energy saving characteristics on the exterior walls of the building and analyze the optimal layout scheme of building exterior wall and thermal insulation system. Finally, the paper study optimal thickness of insulation materials. The paper elaborate scheme of the existing building energy-saving for exterior wall and the scope of application, the system structure and the construction technology. The results showed that： extruded benzene board that can be used for exterior insulation, frame structure filled with wall preferred ceramsite hollow block. The paper can provides reference selection of insulation for building external wall energy-saving transformation scheme.

Evaluation on Combustion Characteristics of Finishing Materials for Exterior Walls

Existing fire test methods reply on measurement of the energy released rate to identify the combustion properties of a material. However, they are inadequate when assessing combustion characteristics of a composite material characterized by vertical flame spread and different inside/outside combustion behaviors. In addition, major factors that affect the flame spread outside the building include the combustion characteristics of materials used as well as air flow around a skyscraper. However, since it is highly difficult to analyze and forecast the air flow from a fire engineering viewpoint, an investigation of the flame spread characteristics of exterior walls of a building depends primarily on the combustion characteristics of materials. Hence, this study examined, using ISO 13785-2 testing method, the temperature changes and vertical flame spread behaviors of one of the finishing materials for exterior walls--（generic ＆ fire-resistant） aluminium panels by a real-scale combustion experiment. According to the results of real-scale experiment, the maximum heat temperature of 987.7 ℃ was recorded seven minutes after the fire test was initiated while the fire-resistant aluminium panels showed the maximum heat temperature of 850.2℃ after exposed for approximately 12 min. The vertical flame spread properties put more emphasis on the time required to reach the maximum temperature rather than its magnitude and there was a five minutes difference between the materials.

基于LabVIEW的智能建筑外墙饰面砖脱空识别软件开发

建筑外墙饰面砖出现脱空现象导致行人出行安全隐患。建筑外墙饰面砖常用锤击检测法识别脱空,识别结果需检测人员的判断。为了进一步提高检测准确率,该文应用LabVIEW开发了智能建筑外墙饰面砖脱空识别软件。该软件基于有限状态机模型开发了数据采集、数据分析和数据管理等功能模块。其中数据分析模块通过提取首波幅值和小波系数积分比特征,运用拉依达准则对数据进行预处理,结合K近邻算法构建脱空识别模型来判别饰面砖是否脱空。并通过制作外墙试件进行实验验证,结果表明软件识别试件的脱空识别率达到92%。因此,该软件能有效识别建筑外墙饰面砖脱空的大小和位置,且运行稳定可靠,在实际工程中有较高的应用价值。

外剪内框结构体系力学计算与抗震性能

为灵活设计商场、库房等大开间建筑的内部空间,提出了一种外剪内框结构体系,即在普通框架结构四周布置剪力墙,将其作为主要抗侧力构件,内部框架结构主要承担竖向荷载。推导了外剪内框结构体系的内力分析方法,提出了框架与剪力墙相对刚度控制参数的计算公式与设计方法。基于某4层框架结构,设计了对应的外剪内框结构,评估了外剪内框结构体系的抗震性能与抗倒塌能力。结果表明,外剪内框结构体系内部框架柱截面面积相对较小,可以实现更大的建筑空间,框架-剪力墙相对刚度的设计方法可用于实际设计。材料用量相同时,外剪内框结构较框架结构抗震性能更好,其抗侧刚度提升30.3%,极限承载力提高7.3%,罕遇地震下基底剪力减小13.8%,顶点位移减小66.3%,最大层间位移角减小74.3%。

装配式混凝土外墙吊装安装施工技术

装配式混凝土外墙吊装安装施工技术,通过预制构件与吊装方式的结合,显著提高了施工效率。以企业公馆工程为例,深入研究装配式混凝土外墙吊装安装施工技术,依据工程实际情况选取合适的装配式混凝土外墙吊装安装施工设备和施工工艺,具体分析装配式混凝土外墙吊装安装施工流程,其关键在于精确控制吊装参数并确保连接件安装质量,同时需灵活应对施工环境的复杂性。试验结果表明,该技术可确保装配式混凝土外墙吊装安装的准确度,提高装配式混凝土外墙吊装安装施工效率。

高层台体建筑外墙吊篮施工技术

本文主要研究的是如何在高层台体建筑外墙施工中使用普通吊篮进行施工。文中以浙江某网红大楼项目为例,针对台体造型高层建筑外墙施工,设计吊篮施工方案,解决高层台体建筑外墙吊篮施工技术难题。

建筑外墙保温节能技术在建筑施工中的应用研究

在建筑行业全面发展背景下,其引发的高能耗问题也应该引起社会各领域的广泛关注,比如外墙的维护结构,不仅是建筑物室内外热量转换的关键环节,而且是建筑能耗的最大空间区域。所以在建筑物外墙保温节能技术应用期间,还应充分联系建筑物的形体系数特征,在合理应用节能技术的基础上,充分体现出建筑外墙保温节能技术的应用优势。

建筑工程外墙绿色节能保温材料检测技术研究

文章旨在探讨建筑工程外墙绿色节能保温材料的检测技术,通过采用文献回顾、实验测试以及数据分析等方法,对保温材料的基本性能、环保性能、耐久性及施工质量进行全面检测,以提高建筑物的保温效果和节能性能。结果显示,绿色节能保温材料在各类评测标准中表现出优良性能,能显著改善建筑保温性能,降低能耗;改进检测技术、优化检测程序和标准化取样,对提高测试精度具有决定性作用;科学精确的检测技术是确保建筑工程外墙环保节能保温材料质量的核心,有助于推动绿色建材产业的稳定进步。

学校教学楼外墙饰面施工技术的应用探讨

本研究从宏观层面深入探讨了学校教学楼外墙饰面施工技术的实际应用,旨在全面保障其美观性、耐久性和安全性。研究分析了关键材料选择、工艺流程优化、质量控制措施以及安全管理等方面,发现高性能涂料与复合板材等新型材料表现优异,先进喷涂技术和定位系统有效提升了施工效率与质量。同时,严格的质量控制与全面的安全管理确保了施工规范与安全,预防了安全事故的发生。通过实证研究,验证了所提施工技术的可行性和有效性,为同类工程提供了重要参考,未来还需关注新技术、新材料的应用与发展,以持续提升施工质量。

外墙保护性修缮工程绿色施工技术应用

文章研究了外墙保护性修缮工程绿色施工技术应用,在掌握具体工程概况的基础上,明确主要工程内容和重难点问题,结合绿色施工概念内涵,从环境保护、节地、节水、节材、节能等方面出发,采取有效的技术措施,更好地贴合项目实际情况,解决实际问题。

节能型建筑外墙保温系统施工技术分析

针对节能型建筑外墙保温系统的施工技术进行了系统研究。通过传热学理论分析,建立了外墙保温系统的等效热阻及节能率计算模型。采用试验方法,测试了保温材料、粘结材料和锚固件的性能参数,并通过正交试验优化了外墙保温系统的施工工艺参数。利用建筑能耗模拟软件,评估了不同气候区节能型外墙保温系统的节能效果,分析了影响节能效果的主要因素。总结了节能型外墙保温系统施工质量控制要点,剖析了常见质量问题的成因,提出了相应的防治措施。研究表明,应用节能型外墙保温系统可显著降低建筑能耗,针对性优化设计和施工是保障其节能效果和施工质量的关键。

Wall Cracks Detection in Aerial Images Using Improved Mask R-CNN

The present paper proposes a detection method for building exterior wall cracks since manual detection methods have high risk and low efficiency.The proposed method is based on Unmanned Aerial Vehicle(UAV)and computer vision technology.First,a crack dataset of 1920 images was established using UAV to collect the images of a residential building exterior wall under different lighting conditions.Second,the average crack detection precisions of different methods including the Single Shot MultiBox Detector,You Only Look Once v3,You Only Look Once v4,Faster Regional Convolutional Neural Network(R-CNN)and Mask R-CNN methods were compared.Then,the Mask R-CNN method with the best performance and average precision of 0.34 was selected.Finally,based on the characteristics of cracks,the utilization ratio of Mask R-CNN to the underlying features was improved so that the average precision of 0.9 was achieved.It was found that the positioning accuracy and mask coverage rate of the proposed Mask R-CNN method are greatly improved.Also,it will be shown that using UAV is safer than manual detection because manual parameter setting is not required.In addition,the proposed detection method is expected to greatly reduce the cost and risk of manual detection of building exterior wall cracks and realize the efficient identification and accurate labeling of building exterior wall cracks.

Overview of Automatic Spraying Technology for Building Exterior Walls

The spraying robot for building exterior walls is an innovative technology in the field of modern construction.This paper discusses its design structure,application cases,technical benefits,and industrial impacts.Research shows that this type of robot improves the efficiency and quality of exterior wall construction.Its intelligent design enhances operation accuracy and safety,reduces costs and risks,and strengthens application ability in complex environments,showing broad application prospects and symbolizing the development trend of intelligence and automation in the industry.In the future,it is necessary to strengthen its intelligence and adaptive ability further,explore multi-function design,promote automation technology,and ensure construction safety and economic benefits.

模卡砌块组合保温墙体热工性能及其经济性分析

随着超低能耗建筑、近零能耗及零能耗建筑的发展,新型外墙围护结构引起广泛地研究和重视.模卡砌块作为一种新型外墙自保温技术,开始在上海、江苏等国内一些发达地区被试点和应用,但目前暂无相应规范指导,其热工性能及经济性仍缺乏系统性研究.文中以夏热冬冷地区某公共建筑为例,采用DeST能耗模拟软件,建立了传统外保温墙体、模卡砌块组合保温墙体三维分析模型,研究了膨胀聚苯板、岩棉板、聚氨酯板、挤塑聚苯板4种不同类型保温材料及6种不同厚度(30、50、70、90、110、130 mm)下模卡砌块组合保温墙体的热工性能.进一步,采用净现值法,对不同工况下的砌块组合保温墙体进行了经济性分析.研究表明:在相同外墙保温厚度下,聚氨酯板的保温效果最佳;不同保温材料厚度对应的净现值都呈现出先上升后下降的趋势,结合净现值和节能率,其最优厚度分别为70、70、40、60 mm,对应的节能率分别在达到我国建筑节能65%的标准上再降低7.08%、6.81%、5.1%、6.5%.

加气混凝土复合保温外墙板连接节点试验研究

通过对钢管锚节点、套筒节点和新型F型节点进行的6组加气混凝土板四分点加载节点极限承载力试验,分析不同板厚下3种节点的节点强度、节点刚度等性能指标。研究表明:新型F型节点力学性能良好,连接可靠,节点极限承载力随板厚增加而增大。新型F型节点可较好地适用在加气混凝土复合保温外墙板体系中。

安徽省典型超低能耗居住建筑外墙材料全生命周期碳排放测算

通过调研安徽省的超低能耗居住建筑,总结出常用的保温形式和保温材料,结合实际项目,得出7种典型外墙构造。从全生命周期角度,对这7种外墙构造在建材生产阶段、建材运输阶段、外墙施工阶段、外墙维护阶段、外墙拆除阶段的碳排放量进行测算。结果表明:建材生产阶段的碳排放量占比最大,达到总碳排放量的70%以上;装配式比非装配式的总碳排放量降低6%左右;内外复合保温外墙的总碳排放量最大,比“夹心保温+外保温外墙”的碳排放量高18%以上,比外保温外墙的碳排放量高11%以上;不同的保温材料和墙体材料对外墙的总碳排放量影响较小。通过分析比较,得出碳排放最优的外墙构造,从建材角度为降碳提供依据和方法。