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61.
介绍了宝钢5m宽厚板轧机工作辊的弯辊/平衡系统,对这一系统的功能,机械、液压设备,压力补偿控制原理,闭环控制系统,参考值,板形及平直度控制,错误及警告等内容做了阐述,着重分析了弯辊系统的压力补偿控制原理。 相似文献
62.
包钢热电厂6^#汽动鼓风机组在一次检修过程中,由于汽轮机提前揭缸造成汽轮机转子轴弯曲,从而引起机组运行过程中振动值偏大。主要介绍了针对该故障的诊断方法和处理过程。 相似文献
63.
Through a semi-phenomenological approach, we have recently derived a simple constitutive relation (HM-V) for aggregates of cubic crystallites with arbitrary texture symmetry. This constitutive relation is quadratic in the texture coefficients of the polycrystal, and it carries four elastic constants. The derivation delivers four explicit formulae which express the four elastic constants of the polycrystal in terms of the three elastic constants of the single cubic crystal and one undetermined parameter. In this paper we use finite-element calculations to check the adequacy of constitutive relation HM-V and to determine the undetermined parameter for copper and iron polycrystals, respectively. 相似文献
64.
A. P. S. Selvadurai A. Shirazi 《International journal for numerical methods in engineering》2005,63(14):2017-2039
A flat rigid elliptical anchorage located in a damage‐susceptible fluid‐saturated poroelastic medium is subjected to an in‐plane load, which induces a pure translation in the plane of the anchor. This paper develops computational estimates for the time‐dependent displacement of the disc anchor for the classical problem that involves Biot consolidation and compares the results with situations where the porous skeleton can experience micro‐mechanical damage that leads to an alteration in both its elasticity and fluid transport characteristics. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
65.
将初参数法与优化方法相结合,提出了阶梯主轴部件刚度的计算方法.这一方法很适合在计算机上对多支承主轴的刚度作精确计算. 相似文献
66.
67.
Partition of unity enrichment for bimaterial interface cracks 总被引:1,自引:0,他引:1
N. Sukumar Z. Y. Huang J.‐H. Prvost Z. Suo 《International journal for numerical methods in engineering》2004,59(8):1075-1102
Partition of unity enrichment techniques are developed for bimaterial interface cracks. A discontinuous function and the two‐dimensional near‐tip asymptotic displacement functions are added to the finite element approximation using the framework of partition of unity. This enables the domain to be modelled by finite elements without explicitly meshing the crack surfaces. The crack‐tip enrichment functions are chosen as those that span the asymptotic displacement fields for an interfacial crack. The concept of partition of unity facilitates the incorporation of the oscillatory nature of the singularity within a conforming finite element approximation. The mixed‐mode (complex) stress intensity factors for bimaterial interfacial cracks are numerically evaluated using the domain form of the interaction integral. Good agreement between the numerical results and the reference solutions for benchmark interfacial crack problems is realized. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
68.
Nam‐II Kim Hee‐Taek Yun Moon‐Young Kim 《International journal for numerical methods in engineering》2004,61(2):274-302
An evaluation procedure of exact static stiffness matrices for curved beams with non‐symmetric thin‐walled cross section are rigorously presented for the static analysis. Higher‐order differential equations for a uniform curved beam element are first transformed into a set of the first‐order simultaneous ordinary differential equations by introducing 14 displacement parameters where displacement modes corresponding to zero eigenvalues are suitably taken into account. This numerical technique is then accomplished via a generalized linear eigenvalue problem with non‐symmetric matrices. Next, the displacement functions of displacement parameters are exactly calculated by determining general solutions of simultaneous non‐homogeneous differential equations. Finally an exact stiffness matrix is evaluated using force–deformation relationships. In order to demonstrate the validity and effectiveness of this method, displacements and normal stresses of cantilever thin‐walled curved beams subjected to tip loads are evaluated and compared with those by thin‐walled curved beam elements as well as shell elements. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
69.
70.
在13根集中荷载作用下钢筋砼双向受弯约束梁斜截面抗剪试验研究的基础上,采用等效梭形截面法,将双向受弯约束梁转化为单向受弯约束梁,并推出集中荷载作用下钢筋混凝土双向受弯约束梁斜截面抗剪强度的计算方法. 相似文献