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31.
Lepikhin P. P. Romashchenko V. A. Tarasovskaya S. A. Korbach V. G. 《Strength of Materials》2003,35(1):52-59
The exactness and stability of the Wilkins method in the investigation of the stress-strain state of axisymmetric anisotropic elastic shells, including thick-walled ones, have been studied for different values of artificial viscosity, pulse load rise and fall time, and different deformation process durations. A comparison of numerical calculations, performed by means of an application software package developed by V. A. Romashchenko on the basis of the Wilkins method, with experimental results, known numerical data, and with calculations using the computation kernel LS-DYNA 3D has been carried out. 相似文献
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通过探讨、分析无缝钢管壁厚偏差产生的原因,提出了改善钢管壁厚偏差的一些措施,并结合实际生产,得出了比较满意的结果。 相似文献
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The aim of this paper is to give a general quantitative requirement which the loop gain must satisfy in order to stabilize a given unstable (possibly nonlinear and time-varying) plant, namely that the gain must exceed one. 相似文献
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G. M. Kulikov S. V. Plotnikova 《International journal for numerical methods in engineering》2002,55(10):1167-1183
The precise representation of rigid body motions in the displacement patterns of curved Timoshenko–Mindlin (TM) shell elements is considered. This consideration requires the development of the strain–displacement relationships of the TM shell theory with regard to their consistency with the rigid body motions. For this purpose a refined TM theory of multilayered anisotropic shells is elaborated. The effects of transverse shear deformation and bending‐extension coupling are included. The fundamental unknowns consist of five displacements and eight strains of the face surfaces of the shell, and eight stress resultants. On the basis of this theory the simple and efficient mixed models are developed. The elemental arrays are derived using the Hu–Washizu mixed variational principle. Numerical results are presented to demonstrate the high accuracy and effectiveness of the developed 4‐node shell elements and to compare their performance with other finite elements reported in the literature. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
39.
ABSTRACT: The traditional small-scale production of boucané, a cured smoked pork-belly product from Réunion, involves several unit operations that are performed in a single step. The aim of this study was to highligh the impact of 4 unit operations (salting, drying, cooking, and smoking) on stability, color, and flavor development in processed pork. These characateristics are the 3 main criteria of boucané's quality. Mass transfer, color, and volatile compounds were measured, analyzed, and compared in 4 products. Results indicated that a major quantity of volatile compounds detected in the processed meat were derived from the smoking process. Color variations were mainly explained by muscle pigment modification due to the cooking process, and by the input of volatile compounds of smoke. 相似文献
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Electrochemical investigations on low-Si alloyed steels with Si content ranging from 0.25 to 3.2 wt.% were carried out in a 0.1 M NaCl borate-buffered solution (pH 8.4) in reducing conditions at 90 °C. Silicon as an alloying element was proved to degrade at first the steel ability to passivate. For longer immersion times, protective effects developed more efficiently on the steel containing 3.2 wt.% silicon. Passive layers electrochemically formed in the transpassive domain on the steel containing 3.2% Si were shown to be significantly different from those grown at rest potential. 相似文献