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1.
为研究T形板肋对预制带肋底板混凝土叠合板弯曲疲劳性能的影响,对3块T形肋底板叠合板和1块整浇板进行弯曲疲劳性能对比试验,主要考察T形板肋与疲劳荷载幅值对试件疲劳破坏形态及疲劳损伤程度的影响,得到了在不同疲劳循环加载次数下的跨中动位移、混凝土应变、预应力筋应变、残余变形等,分析了在不同疲劳循环加载次数下的刚度退化情况、荷载-应变分布规律、裂缝分布规律及剩余承载力等。研究结果表明,经历200万次疲劳循环加载后,T形肋底板叠合板无明显的刚度和强度退化,增设T形板肋的叠合板能达到与整浇板相同的弯曲疲劳性能;T形肋底板叠合板正截面弯曲疲劳强度计算可采用普通预应力混凝土受弯构件正截面疲劳应力验算的4个假定,最终以此建立了其正截面弯曲疲劳强度验算方法。  相似文献   

2.
Based on the analysis of the status of building construction in China, the development of Assembled Structure System (ASS) can solve not only the problems in construction, but also is the key for realization of building industrialization. On the basis of technique innovations, a study on the structural performance, construction method and precast production of ASS should be carried out to inherit the old one and overcome its demerits. The process reengineering should be done in the construction enterprise to promote the development of building industrialization.  相似文献   

3.
At present, there is a lack of study on the destruction mechanism and characteristic in the investigation after gas explosion accident. The destruction and treatment scheme of two accidents happened in Shanghai were introduced. According to the precast slab and poured slab that badly damaged in the two accidents, the anti-explosion ability of the slab was obtained through theoretical calculation and numerical simulation, and then explosion overpressure was estimated. The reason why the overpressure differs little but the destruction differs much in the two accidents and the destruction characteristic of the gas explosion to the building were all analyzed. It is considered that: 1) the anti-explosion ability of the poured slab is far superior to the one-way precast slab; 2) Room with the ignition source is impacted by the overpressure directly and the damage is most serious, while the destruction of the other rooms is caused by the vibration, and its influence is smaller as the house is far from the explosion.  相似文献   

4.
New types of precast concrete ribbed panels are developed in order to adapt to the complex loading conditions and different floor spans. Based on the yield line theory, equations for the ultimate bearing capacity and yield patterns of two-way composite slabs of different edge conditions and under uniformly distributed loading are developed, and the simplified formulas for the ultimate moment per unit width are proposed. The plastic limit analyses of two examples on the simple support and the fixed support are conducted, and the calculation results show good agreement with the experimental data.  相似文献   

5.
预应力装配混凝土复合墙板抗震性能试验研究   总被引:1,自引:0,他引:1  
结合砌体结构的发展现状和住宅产业化的发展趋势,提出一种“预应力装配混凝土复合墙板”,以期望在中小城镇低层建筑民用房屋中发展一种新的结构形式来对砌体结构进行补充。为了考察该复合墙板的抗震性能,对2块不同预应力度的试件进行了拟静力试验。得到了相应试件的抗震性能指标,显示该墙板具有较好的承载能力和变形性能,分析认为所提出的墙板可以达到8度区低层民用房屋的应用要求,可以作为砌体承重墙的一种替代形式,并且对该墙板相关构造提出了改进建议。  相似文献   

6.
This paper first presented the architecture of the CAD system for space - grid structures based on ObjectARX, then some key technologies were studied to realize the system, such as interface control method on MFC, graphic database and parametric drive. A CAD system for space -grid structures based on ObjectARX was develooed with AutoCAD API and the Object- oriented technique.  相似文献   

7.
To study the technique of surface reconstruction for Chinese medicinal materials from its cross-sectional images and to display its three dimensional structure.The pattern recognition technique is used to complete the classification and matching of various structures, then the triangle surface approximation is used to produce the 3D surface of the structure.The 3D structure is reconstructed and can be viewed by flexible way based on SGI workstation. The technique and method provided by this paper is contributive to the study and view of various structure of Chinese medicinal materials, and is available to biomedical image processing field.  相似文献   

8.
By adopting seven kinds of adhesive resins, the mechanical properties of the interface between pultruded Basalt fiber reinforced polymer plates and cast-in-place concrete is studied according to two groups of stretching double-shear test. And it is compared with the dry-bonding interface between BFRP plates and the precast concrete. Further study is conducted by comparing the damage features, load-displacement curves, effective bond length, bond slip relationship and interface fracture energy between the two interfaces. It is found that the effective bond length of the two interfaces are similar, but the bond strength of the wet-bonding is about half of the dry-bonding. Finally, the shear stress-slip model is proposed for the wet-bonding interface based on the experimental data.  相似文献   

9.
For the convenience of industrialized production and site operation,specification design of PPCRP (precast prestressed concrete ribbed panels) is discussed. In order to obtain ultimate bearing capacity,bending rigidity and crack resistance,four PPCRP with two types of spans are studied,and the results show that PPCRP can satisfy the requirements of bearing capacity in construction phase and can serve as stay-in place formwork. To verify the mechanical property,shear behavior on contact interface of composite member and moment redistribution factor of continuous composite member,two single-span composite members and one two-span continuous composite member are studied. It is indicated that computational method for bearing capacity of composite member can be the same as cast-in-situ concrete slab. Besides,section strain analysis for composite member in two-loading is conducted,which suggests that thickness of bottom board can be used as calculated height with the consideration of two-loading.  相似文献   

10.
Honeycomb meshes are topological structures for connecting processors within parallel computers. The unicast routing strategy on honeycomb meshes are studied. It is indicated that a previous known routing algorithm may suffer from deadlock. A deadlock-free routing algorithm known as the XYZ-ROUTE algorithm is presented by employing the classical virtual channel technique. This algorithm is improved to make it work properly in the presence of convex faults.  相似文献   

11.
为了研究橡胶树中Profilin 蛋白的功能,利用橡胶树Profilin 基因部分已知序列设计引物,采用 3′-RACE技术获得Profilin 基因完整开放阅读框,该基因编码131 个氨基酸,含有一个保守的PROF结构域。在HbPro1 蛋白中没有预测到跨膜区和信号肽,二级结构分析表明HbPro1 属于混合型蛋白。对 25 个Profilin 蛋白系统进化分析表明,HbPro1 在进化上具有保守性,属植物类Profilin 蛋白家族。 HbPro1 基因的克隆和生物信息学分析为深入研究其功能奠定了基础。  相似文献   

12.
The small-angle X-ray scattering(SAXS) technique is one of chief tools to study structures of macromolecules and meso-structures.As users of synchrotron radiation small angle X-ray scattering experimental station are increasing rapidly,it is necessary that data processing techniques are provided with them.Some data processing techniques are discussed.It includes the method to become greater data amount of lower angle region and the data must be extrapolated to hole special for the data from experiment,a sample is analyzed.  相似文献   

13.
谢小丹 《中国农学通报》2009,25(19):309-313
本文通过对闽西北烟-稻轮作区2005-2007年度农田渠道建设中采用的浆砌石、预制混凝土渠槽、现场浇筑混凝土等三种防渗衬砌结构的渠道造价进行分析,结合防渗效果、工程效益、运行情况和使用年限等方面的比较,选择出造价经济、建设质量容易控制、防渗水效果好、工程效益高、运行情况好、使用年限长的现场浇筑混凝土结构作为渠道衬砌的主要方式。由于在现场浇筑混凝土的施工中采用了双面立模、钢架固定的立模新工艺,从而达到整体浇筑、一次成型的施工目的。实践证明此方法增强了渠道的密实度和强度,渠面麻点少、糙率减小,提高了防淤抗冲性、抗磨性,渠道线条更加流畅,美观度好,从而增加了过水能力,方便了管护运行,延长了渠道的使用年限。  相似文献   

14.
表层嵌贴预应力FRP板条加固钢筋混凝土结构技术可充分发挥FRP材料强度,且不需设置永久锚具,具有较大的潜力。以试验得到的嵌贴FRP混凝土粘结滑移关系为基础,建立了嵌贴预应力CFRP板条与混凝土的粘结应力微分方程,并根据边界条件推导了方程的解析解,得到了嵌贴预应力CFRP板条放张后界面粘结应力、CFRP拉伸应力的分析模型。与试验结果的比较表明,该模型得出的界面粘结应力及CFRP拉伸应力与试验结果吻合较好。在此基础上,考虑放张后CFRP混凝土界面不出现剥离的条件,分析了粘结界面能抵抗的最大容许预应力。  相似文献   

15.
The objective of this work was to adapt the FT Raman spectroscopy analysis in the differentiation of haploid and diploid kernels in maize, developing a new efficient, agile, precise, and nondestructive methodology. The main difference observed in FT Raman readings was a peak in the region between 1600 and 1700 cm−1 in possibly haploid kernels. It was possible to correlate the characteristics of the kernels with the presence of the R1-nj gene and the readings obtained in the Raman spectrometry technique. Most of the kernels previously classified as haploid showed positive values for principal component analysis (PCAs), indicating a correlation in the identification of haploids by the techniques adopted. The identification of haploids by R-Navajo was superior to FT Raman. However, FT Raman spectroscopy is an agile analysis technique that enables the development of non-invasive and non-destructive analytical methods in maize kernels, in addition to providing relevant information about the chemical structures present in the composition of the samples.  相似文献   

16.
牡丹胚珠的结构观察与珠心的非酶法分离   总被引:1,自引:1,他引:0  
为了获得牡丹胚珠内的珠心,在对牡丹胚珠的结构进行观察的基础上,研究了牡丹珠心的非酶法分离技术。以新鲜和酒精溶液固定的牡丹胚珠为材料,利用荧光显微镜、84消毒液的整体透明技术及切片技术,研究了牡丹胚珠的结构,并以新鲜的牡丹胚珠为材料,在解剖镜下利用胶块对牡丹的珠心等结构进行了非酶法分离。结果表明:在牡丹胚珠的2层珠被中,外珠被很厚,容易除去,而内珠被的外层容易与珠被绒毡层脱离并除去。在牡丹的胚珠中,只有珠被绒毡层能够发出清晰的荧光。在解剖镜下,利用胶块依次将牡丹胚珠的外珠被、内珠被外层和珠被绒毡层除去后,可分离出具有原有形态的牡丹珠心。  相似文献   

17.
A vast amount of information data must be input before finite element analysis of steel frames, such as node information, element information and load information. It is necessary to develop a computer aided design system with 3D interactive function. A CAD system for steel frame based on object ARX is developed with AutoCAD API and the Object -oriented technique. In this paper, some key programming technologies is studied, including design of structures, identification of floor system, also, it has presented the relevant implementing code.  相似文献   

18.
Isolation technique was not only applied for middle or low buildings, but also recently it was applied to high rise buildings. For high rise buildings, multi order vibration should be considered for upper structure isolation and bend deformation should be taken into account in gross deformation because of large height to width ratio. On the basis of previous studies, calculation method of equivalent model for regular isolated structure with bend shear deformation characteristic was proposed according to equivalent criteria after the analysis for some model structures. With the proposed model, handwork calculation of earquake response for isolated structure can be simply completed and design efficiency of isolation structure was improved. Based on the case studies, the equivalency of proposed model was approved.  相似文献   

19.
褐藻胶经过稀HCl降解,pH值2.85分级获得2种聚糖粗品。通过dowex阴离子交换分离,浓度0.5~2.0 mol/L的醋酸梯度洗脱提纯,即获得高纯度的聚甘露糖醛酸(PM)和聚古罗糖醛酸(PG)。采用高效液相色谱技术对其分子量及纯度进行初步测定,利用核磁共振技术对其分子结构和纯度进行最终鉴定。由核磁共振图谱可得其结构保持了M,G的原有结构,且制得的2种聚糖纯度均在95%以上。  相似文献   

20.
Real-time substructring testing is under rapid development. is a hybrid computational-experimental technique, and its challenge is to ensure that the numerical substructure and the experimental substructure interact in real time, which requires efficient numerical integration methods. With this mind, based on the Rosenbrock real-time integrator, a coupled time integration method is proposed which enables completely parallel computation. By virtue of a Single-DoF split-mass test problem, stability and accuracy analyses are performed theoretically for the coupled method. Moreover, numerical simulations on a Three-DoF split-mass system are conducted to further investigate the convergence and other properties of the coupled method. The theoretical analysis and the numerical simulations reveal that the method exhibits favourable stability and second order accuracy. Compared with direct time integration methods, the proposed method is more suitable for Real-Time Substructuring Tests of complicated structures and relevant hybrid simulations.  相似文献   

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