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排序方式: 共有763条查询结果,搜索用时 31 毫秒
11.
Effects of coating thickness and residual stresses on the bond strength of ASTM C633-79 thermal spray coating test specimens 总被引:1,自引:0,他引:1
D. J. Greving J. R. Shadley E. F. Rybicki D. J. Greving J. R. Shadley E. F. Rybicki 《Journal of Thermal Spray Technology》1994,3(4):371-378
Wire-arc-sprayed nickel-aluminum is widely used in the aircraft industry for dimensional restoration of worn parts and as
a bond coat for thermal barrier coatings and other top coats. Some repair applications require thick coatings, which often
result in lower bond strength. A mechanism being investigated to ex-plain this decrease in bond strength is the free edge
effect, which includes both coating residual stresses and coating thickness. The layer-removal method was used to determine
experimentally the residual stresses in wire-arc-sprayed nickel-aluminum coatings of different thicknesses. Bond strength
evalu-ations were performed using an improved ASTM C 633-79 test specimen. Finite-element analysis and fracture mechanics
were used to investigate the effects of coating thickness and residual stress state on coating bond strength. 相似文献
12.
R. Sadeler A. Ozel I. Kaymaz Y. Totik 《Journal of Materials Engineering and Performance》2005,14(3):351-355
The effect of tensile prestraining-induced residual stress on the fatigue life of notched steel parts was investigated. The
study was performed on AISI 4140 steel. Rotating bending fatigue tests were carried out on semicircular notched specimens
with different notch radii in the as-quenched and tempered conditions. Metallography of the specimens was performed by means
of light optical microscopy. The finite-element method was used to evaluate the residual stress distribution near the notch
region. Fatigue tests revealed fatigue life improvement for notched specimens, which changes depending on the notch radii
and applied stress. Scanning electron microscopy was used to examine the fracture surfaces of the specimens. 相似文献
13.
14.
1.IntroductionApproximately15milliontonsofsteeltubeandpipeproductsareconsumedintheUnitedStatesannually.Mechanicaltubesarethefeedstocksusedinthemanufactureofrollingelementbearings,hydrauliccylinders,alldagreatvarietyofpowertransmissioncomponents.Steeltubesarealsoemployedinthedrillstringsforoilandnaturalgasexplorationandrecovery.Steelpipesareusedinthetransportofgas,oilandotherfluids.ControlledThermal--MechanicalProcessing(CTMP)involvesprecisecontroloftemperature,mechanicaldeformation,andmicr… 相似文献
15.
Crystallographic analysis on small fatigue crack propagation behaviour of a nickel-based single crystal superalloy
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W. Qiu X. Ma S. Rui H.-J. Shi 《Fatigue & Fracture of Engineering Materials & Structures》2017,40(1):3-11
In situ observations by scanning electron microscopy show that small fatigue cracks in a nickel-based single crystal superalloy are inclined to the loading direction and propagate in dominant crystallographic manners. In order to evaluate the driving forces for inclined crack propagation, three-dimensional anisotropic linear elastic finite-element analysis is conducted. The plastic zone size on the dominant slip plane has been calculated and proposed to correlate the fatigue crack growth. It is shown that this parameter takes into account both material anisotropy and octahedral fracture modes, and it can effectively characterize small crack propagation behaviour. 相似文献
16.
《国际计算机数学杂志》2012,89(1):112-127
This paper presents a finite-element dimension splitting algorithm (DSA) for a three-dimensional (3D) elliptic equation in a cubic domain. The main idea of DSA is that a 3D elliptic equation can be transformed into a series of two-dimensional (2D) elliptic equations in the X–Y plane along the Z-direction. The convergence speed of the DSA for a 3D elliptic equation depends mainly on the mesh scale of the Z-direction. P 2 finite-element discretization in the Z-direction for DSA is adopted to accelerate the convergence speed of DSA. The error estimates are given for DSA applying P 1 or P 2 finite-element discretization in the Z-direction. Finally, some numerical examples are presented. We apply the parallel solving technology to our numerical examples and obtain good parallel efficiency. These numerical experiments test and verify theoretical results. 相似文献
17.
Allan P. Engsig-Karup Jan S. Hesthaven Harry B. Bingham Per A. Madsen 《Journal of Engineering Mathematics》2006,56(3):351-370
A discontinuous Galerkin finite-element method (DG-FEM) solution to a set of high-order Boussinesq-type equations for modelling
highly nonlinear and dispersive water waves in one horizontal dimension is presented. The continuous equations are discretized
using nodal polynomial basis functions of arbitrary order in space on each element of an unstructured computational domain.
A fourth-order explicit Runge-Kutta scheme is used to advance the solution in time. Methods for introducing artificial damping
to control mild nonlinear instabilities are also discussed. The accuracy and convergence of the model with both h (grid size) and p (order) refinement are confirmed for the linearized equations, and calculations are provided for two nonlinear test cases
in one horizontal dimension: harmonic generation over a submerged bar, and reflection of a steep solitary wave from a vertical
wall. Test cases for two horizontal dimensions will be considered in future work. 相似文献
18.
钢骨高强混凝土偏压柱受力分析 总被引:1,自引:1,他引:1
目的研究钢骨高强混凝土柱在竖向偏心载荷作用下的受力性能.方法运用有限元法和有限条带法。考虑了材料的非线性以及构件的侧向位移与二次弯矩的相互影响,编制了钢骨高强混凝土偏压柱由开始加载直至破坏的受力全过程分析程序.结果根据程序运行结果,分析、讨论了偏心矩、混凝土强度、钢骨含钢量、纵筋配筋率及长细比等参数对钢骨高强混凝土偏压柱受力性能的影响.从而得出,钢骨含钢量越大,构件的承载能力提高越明显,钢骨的合理含钢量范围应在4%-8%.结论在一定范围内提高纵筋的配筋率,将会提高构件的承载力,并在一定程度上提高构件的延性.有限元法能够较好地模拟钢骨高强混凝土偏压柱的受力过程,并分析其工作特性. 相似文献
19.
20.
结冰传感器探头的动态特性分析 总被引:2,自引:0,他引:2
振管模态参数的测试是结冰传感器调试的前提,利用有限元法对结冰传感器探头简化模型进行了模态分析,预估其模态参数.介绍了试验模态分析方法的原理和测试系统,通过该方法对传感器实际结构进行了精确测试,对测试结果进行了分析,验证了有限元法的分析结果和探头结构理论设计的合理性,为传感器谐振电路的调试奠定了基础,提高了传感器的调试效率;并对振管轴向振动固有频率的温度特性进行了分析,为传感器的温度补偿提供了依据. 相似文献