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为研究YX75-200-600和YX76-344-688压型钢板-混凝土组合楼板的剪切粘结承载力和剪切粘结性能,进行了18块足尺寸简支压型钢板-混凝土组合楼板的载荷试验,并进行了相关的分析。试验结果表明:18个试件的破坏形态均为剪切粘结破坏,影响剪切粘结性能的主要因素有剪跨、压型钢板厚度和栓钉。由试验数据分析得到的端部有栓钉YX75-200-600压型钢板-混凝土组合楼板的剪切粘结系数m,k为228.12,-0.015,YX76-344-688压型钢板-混凝土组合楼板的剪切粘结系数m,k为246.9,-0.0028。 相似文献
164.
《Journal of Nuclear Science and Technology》2013,50(5):284-291
Approximate solutions to the one-velocity time dependent neutron transport equation are derived by means of the eigenfunction expansion method of Case for a slab geometry. A finite set of discrete time eigenvalues is determined by a simple formula. This formula, which is derived for the case of large slab thickness, is found to be valid also for fairly thin slabs. Each time eigenvalue generates a pair of spatial modes. The expansion coefficients to these modes are examined by numerical evaluation for various slab thicknesses. Higher spatial modes are found to play an important role in the transient time evolution of neutrons. 相似文献
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In this paper a robust model is presented based on the previous layer procedure developed by the author to also take into account the effects of concrete spalling on the behaviour of concrete slabs under fire conditions. In this study, a detailed analysis of a uniformly loaded reinforced concrete slab subject to different degrees of concrete spalling under a standard fire regime is first carried out. Further, a series of analysis of floor slabs with different degrees of concrete spalling is also performed on a generic reinforced concrete building. A total of 16 cases have been analysed using different degrees of spalling on the slabs, with different extents and positions of localised fire compartments. It is clear that adjacent cool structures provide considerable thermal restraint to the floor slabs within the fire compartment. And it is evident that the compressive membrane force within the slabs is a major player in reducing the impact of concrete spalling on the structural behaviour of floor slabs in fire. 相似文献
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This paper proposes a multi-level assessment strategy for reinforced concrete bridge deck slabs. The strategy is based on the principle of successively improved evaluation in structural assessment. It provides a structured approach to the use of simplified as well as advanced non-linear analysis methods. Such advanced methods have proven to possess great possibilities of achieving better understanding of the structural response and of revealing higher load-carrying capacity of existing structures. The proposed methods were used for the analysis of previously tested two-way slabs subjected to bending failure and a cantilever slab subjected to a shear type of failure, in both cases loaded with concentrated loads. As expected, the results show that more advanced methods yield an improved understanding of the structural response and are capable of demonstrating higher, yet conservative, predictions of the load-carrying capacity. Nevertheless, the proposed strategy clearly provides the engineering community a framework for using successively improved structural analysis methods for enhanced assessment in a straightforward manner. 相似文献
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This paper presents results from numerical studies on the effect of critical factors governing the shear response on prestressed concrete (PC) hollowcore slabs exposed to fire. A validated three dimensional finite element model is applied for evaluating failure of fire exposed prestressed concrete (PC) hollowcore slabs under different limiting states, including through shear. This model accounts for temperature induced property degradation in concrete and prestressing strands, cracking in concrete, varying fire exposure, loading and restraint conditions. The factors varied in the parametric study include, slab depth, load level, loading pattern, axial restraint, level of prestressing, and fire scenario. Results from parametric studies show that slab depth, load level, loading pattern, axial restraint, level of prestressing and fire scenario have significant influence on the fire response of PC hollowcore slabs, and failure under these conditions can occur through shear limiting state prior to reaching flexural limiting state. Results from parametric studies are further utilized to propose a simplified approach for evaluating shear capacity PC hollowcore slabs under fire conditions. 相似文献
170.
不同粒度钼粉对板材组织的影响 总被引:1,自引:0,他引:1
通过将不同粒度及形貌的钼粉进行压制烧结成为板坯,再进行轧制加工及不同温度的退火处理观察其显微组织后发现:在同样的烧结工艺下,大粒度钼粉及小粒度钼粉烧结组织的晶粒较大,普通粒度钼粉烧结组织的晶粒细小;在同样的加工工艺下,普通粒度钼粉制备的板坯组织粗大,大粒度钼粉制备的板坯组织较细,小粒度钼粉制备的板坯组织最细小;在1 150~1 200℃退火时,普通粒度钼粉制备板坯的再结晶晶粒数少而晶粒粗大,大粒度钼粉板坯的再结晶晶粒数次之,小粒度钼粉板坯的再结晶晶粒最小;1 300℃时小粒度钼粉板坯的晶粒长大速度最快,而普通粒度钼粉板坯次之,大粒度钼粉板坯最慢。 相似文献