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静定结构在不稳定温度场中的变形计算 总被引:1,自引:0,他引:1
张福林 《西安矿业学院学报》1996,16(1):20-23
建筑结构受温度作用时将产生温度变形,本文推导出静定结构温度沿截面呈曲线变化时,温度变形的近似计算公式。 相似文献
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钢筋混凝土结构火灾反应的研究 总被引:1,自引:0,他引:1
在火灾的高温作用下,钢筋混凝土材料强度下降,变形增大,刚度减小,甚至发生内力重分布,以致改变结构的破坏机构和极限荷载。从构件和结构温度反应、材料分析、构件分析和结构整体分析四个方面探讨了钢筋混凝土结构的火灾反应。 相似文献
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本文根据短柱壳的力学原理,对软岩巷道锚喷与金属支架联合支护进行内力计算,阐述了这种联合支护结构的内力及变形特点,危险断面位置以及截面强主设计控制因素等同的地形为这种以护结构设计提供了一定的理论依据。 相似文献
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详细分析了五河口斜拉桥合拢各种影响因素,包括合拢温度、高差的处理、压重以及体系转换对桥梁结构内力以及线形的影响,为桥梁的顺利合拢以及结构合理受力提供技术支持。 相似文献
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烧结主厂房超长低跨部分因工艺条件限制不能设置伸缩缝。文中对低跨部分的变形特点、温度应力和收缩应力进行分析,通过简化计算得出了应力结果。并列举了工程计算实例。 相似文献
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为了探明MgO掺杂对高炉渣熔融调质钢渣(混合渣)物相组成与结构的影响,采用X射线衍射仪和SEM-EDS扫描电镜对高温调质后混合渣物相组成及形貌进行了分析。结果表明,掺杂MgO能有效抑制MgFe2O4相和非胶凝性Ca2Al2SiO7物相生成、促进MgFeAlO4物相生成,提高混合渣熔点。MgO掺杂量2%的高温调质混合渣截面呈层状结构,内层MgFeAlO4物相占比增加,孔洞均匀且细小;中间具有层状结构的MgFe2O4尖晶石包裹在MgFeAlO4物相周围;外层Ca2Al2SiO7物相孔洞均匀,致密度适中;此结构的混合渣是较好的重金属离子过滤材料。 相似文献
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Sheng-Rong Xie Er-Peng Li Fu-Lian He Shou-Bao Zhang Guang-Chao Zhang Mao-Yu Pang 《煤炭学报(英文版)》2013,19(2):126-132
In order to solve the surrounding rock control problem of large section gangue replacement roadway under complicated conditions, this paper analyzed the impact to the roadway controlling produced by the geological conditions such as high ground stress, folded structure tilted roof asymmetry and soft wall rock, and built the tilt layered roof structural mechanics model to clarify the increase span mechanism of the weak coal instability. Then, we proposed the combined control system including roof inclined truss cable, coal-side cable-channel steel and intensive bolt support. And then by building the structural mechanics model of roof inclined truss cable system, the support principle was described. Besides, according to this model, we deduced the calculation formula of cable anchoring force and its tensile stress. Finally surrounding rock control technology of large section roadway in fold coal pillar area was formed. Field practice shows that the greatest roof convergence of gangue replacement roadway is 158 mm and coal-side deformation is 243 mm. Roadway deformation is controlled effectively and technical support is provided for replacement mining. 相似文献
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建立车架中部牵引梁2种方案(方案一:圆形截面结构牵引梁;方案二:正八边形截面结构牵引梁)的三维模型和有限元模型,在边界条件相同的情况下,选择极限工况对2种方案进行强度和刚度的计算、分析、比较。其强度和刚度计算结果为:方案一最大应力为141.5 MPa,最大变形为 0.53 mm;方案二最大应力为 137.5 MPa,最大变形为0.503 mm;从计算结果上看,方案二的应力和变形均小于方案一,所以方案一为较优方案。从制作工艺上对2种方案进行比较,方案一中牵引梁为大直径圆形截面结构,需要用专用设备进行成型加工,制作工艺复杂;方案二中牵引梁为正八边形截面结构,可有2块钢板分别折弯、对焊而成,制作工艺简单,从工艺上可以得出方案二为较优方案。比较得出,方案二正八边形截面结构牵引梁的强度和刚度均能满足要求,工艺性更好,为较优方案。 相似文献
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Dipl.-Ing. Katharina Sophie Ragger Robert Kaiser Jürgen Paal Rainer Fluch Bruno Buchmayr 《BHM Berg- und Hüttenm?nnische Monatshefte》2014,159(5):214-219
Cold pilgering is a complex process for manufacturing seamless tubes. By cold pilgering, the outer diameter and wall thickness of a preliminary hollow are reduced. The compressive mean normal stress makes high reductions in cross section and concurrently excellent surface qualities possible. Even though the deformability is good, sometimes cracks at the inner surface of the tube can be observed. The aim of the paper is to investigate the damage mechanism by using a 3D finite element model. The cause for crack formation and the influence of the ingoing hollow’s quality are discussed. The paper includes simulated rolling processes based on identic process parameters with three different hollow geometries. Apart from the rolling forces, a comparison of the calculated damage parameters is done. Furthermore, the analysis of specific components within the deformation zone makes a deeper knowledge of the process possible. 相似文献