全文获取类型
收费全文 | 275篇 |
免费 | 5篇 |
国内免费 | 5篇 |
专业分类
化学 | 1篇 |
力学 | 223篇 |
综合类 | 5篇 |
数学 | 48篇 |
物理学 | 8篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 3篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 8篇 |
2015年 | 7篇 |
2014年 | 2篇 |
2013年 | 7篇 |
2012年 | 3篇 |
2011年 | 8篇 |
2010年 | 4篇 |
2009年 | 10篇 |
2008年 | 16篇 |
2007年 | 11篇 |
2006年 | 13篇 |
2005年 | 17篇 |
2004年 | 25篇 |
2003年 | 12篇 |
2002年 | 17篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 7篇 |
1998年 | 7篇 |
1997年 | 14篇 |
1996年 | 4篇 |
1995年 | 7篇 |
1994年 | 10篇 |
1993年 | 9篇 |
1992年 | 10篇 |
1991年 | 10篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有285条查询结果,搜索用时 31 毫秒
131.
In the present paper dynamic stress intensity factor and strain energy density factor of multiple cracks in the functionally graded orthotropic half-plane under time-harmonic loading are investigated. By utilizing the Fourier transformation technique the stress fields are obtained for a functionally graded orthotropic half-plane containing a Volterra screw dislocation. The variations of the material properties are assumed to be exponential forms which the equilibrium has an analytical solution. The dislocation solution is utilized to formulate integral equation for the half-plane weakened by multiple smooth cracks under anti-plane deformation. The integral equations are of Cauchy singular type at the location of dislocation which are solved numerically to obtain the dislocation density on the faces of the cracks. The dislocation densities are employed to determined stress intensity factor and strain energy density factors (SEDFs) for multiple smooth cracks under anti-plane deformation. Numerical examples are provided to show the effects of material properties and the crack configuration on the dynamic stress intensity factors and SEDFs of the functionally graded orthotropic half-plane with multiple curved cracks. 相似文献
132.
基于二维弹性理论, 利用Hellinger-Reissner变分原理, 通过引入对偶变量, 推导
了双参数地基上正交各向异性梁平面应力问题的辛对偶方程组; 采用分离变量法和本征展
开方法, 将原问题归结为求解零本征值本征解和非零本征值本征解, 得到了适用于任意横纵
比的梁的解析解. 由于在求解过程中不需要事先人为地选取试函数, 而是从梁的基本方程出
发, 直接利用数学方法求出问题的解, 使得问题的求解更加合理化. 其中, 地基对梁的力学
行为的影响看作是侧边边界条件, 类似于外载, 可通过零本征解的线性展开来评价, 非零本
征值本征解对应圣维南原理覆盖的部分. 还利用哈密顿变分原理, 给出了两端固支梁的
一种新的改进边界条件. 编程计算了细梁和深梁等算例, 研究了地基上梁的变形沿着厚度方
向的变化特性, 验证了辛方法的有效性. 相似文献
133.
Mousa Khalifa Ahmed 《Mathematical Methods in the Applied Sciences》2011,34(14):1789-1800
Based on the framework of the Flügge's shell theory, the transfer matrix approach and the Romberg integration method, this paper presents the vibration behavior of an isotropic and orthotropic oval cylindrical shell with parabolically varying thickness along its circumference. The governing equations of motion of the shell, which have variable coefficients are formulated and solved. The analysis is formulated to overcome the mathematical difficulties related to mode coupling, which comes from variable curvature and thickness of shell. The vibration equations of the shell are reduced to eight first‐order differential equations in the circumferential coordinate and by using the transfer matrix of the shell, these equations can be written in a matrix differential equation. The proposed model is adopted to get the vibration frequencies and the corresponding mode shapes for the symmetrical and antisymmetrical modes of vibration. The sensitivity of the frequency parameters and the bending deformations to the shell geometry, ovality parameter, thickness ratio, and orthotropic parameters corresponding to different type modes of vibration is investigated. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
134.
A.M.ZENKOUR 《应用数学和力学(英文版)》2011,32(4):507-520
An analytical solution is presented for the rotation problem of a two-layer composite elastic cylinder under a plane strain
assumption. The external cylinder has variable-thickness formulation, and is made of a heterogeneous orthotropic material.
It contains a fiber-reinforced viscoelastic homogeneous isotropic solid core of uniform thickness. The thickness and elastic
properties of the external cylinder are taken as power functions of the radial direction. By the boundary and continuity conditions,
the radial displacement and stresses for the rotating composite cylinder are determined. The effective moduli and Illyushin’s
approximation methods are used to obtain the viscoelastic solution to the problem. The effects of heterogeneity, thickness
variation, constitutive, time parameters on the radial displacement, and stresses are investigated. 相似文献
135.
136.
Materials get damaged under shear deformations. Edge cracking is one of the most serious damage to the metal rolling industry, which is caused by the shear damage process and the evolution of anisotropy. To investigate the physics of the edge cracking process, simulations of a shear deformation for an orthotropic plastic material are performed. To perform the simulation, this paper proposes an elasto-aniso-plastic constitutive model that takes into account the evolution of the orthotropic axes by using a bases rotation formula, which is based upon the slip process in the plastic deformation. It is found through the shear simulation that the void can grow in shear deformations due to the evolution of anisotropy and that stress triaxiality in shear deformations of (induced) anisotropic metals can develop as high as in the uniaxial tension deformation of isotropic materials, which increases void volume. This echoes the same physics found through a crystal plasticity based damage model that porosity evolves due to the grain-to-grain interaction. The evolution of stress components, stress triaxiality and the direction of the orthotropic axes in shear deformations are discussed. 相似文献
137.
The nonlocal nonlinear vibration analysis of embedded laminated microplates resting on an elastic matrix as an orthotropic Pasternak medium is investigated. The small size effects of micro/nano-plate are considered based on the Eringen nonlocal theory. Based on the orthotropic Mindlin plate theory along with the von Kármán geometric nonlinearity and Hamilton's principle, the governing equations are derived. The differential quadrature method (DQM) is applied for obtaining the nonlinear frequency of system. The effects of different parameters such as nonlocal parameters, elastic media, aspect ratios, and boundary conditions are considered on the nonlinear vibration of the micro-plate. Results show that considering elastic medium increases the nonlinear frequency of system. Furthermore, the effect of boundary conditions becomes lower at higher nonlocal parameters. 相似文献
138.
L. Nazarenko L. P. Khoroshun W. H. Müller B. R. Wille 《Mechanics of Composite Materials》2009,45(1):11-20
A model of deformation of stochastic composites subjected to microdamage is developed for the case of orthotropic materials
with microdamages accumulating in the fibers. The composite is treated as a matrix strengthened with elliptic fibers with
orthotropic elastic properties. The fractured microvolumes are modeled by a system of randomly distributed quasi-spherical
pores. The porosity balance equation and relations for determining the effective elastic moduli for the case of a fibrous
composite with orthotropic components are used as the fundamental relations. The fracture criterion is given as a limit value
of the intensity of average shear stresses occurring in the undamaged part of the material, which is assumed to be a random
function of coordinates and is described by the Weibull distribution. Based on an analytical and numerical approach, the algorithm
for determining the nonlinear deformation properties of such a material is constructed. The nonlinearity of composite deformations
is caused by the accumulation of microdamages in the fibers. By using a numerical solution, the nonlinear stress–strain diagrams
for an orthotropic composite in uniaxial tension are obtained.
Translated from Mekhanika Kompozitnykh Materialov, Vol. 45, No. 1, pp. 17–30, January–February, 2009. 相似文献
139.
Influence of magnetic field on free vibrations in elastodynamic problem of orthotropic hollow sphere
The effect of magnetic field on the plane vibrations for an elastodynamic orthotropic sphere is studied. Equations of elastodynamic problems of the orthotropic hollow sphere in terms of displacement are solved. The numerical results of the frequency equations in the presence of magnetic field are discussed and shown graphically. Compar-isons are made with the result in the presence and absence of magnetic field in the case of orthotropic sphere. The results show that the effect of magnetic field is very pronounced. 相似文献
140.
Adopting the complex function approach, the paper studies the stress intensity factor in orthotropic bi-material interface cracks under mixed loads. With consideration of the boundary conditions, a new stress function is introduced to transform the problem of bi-material interface crack into a boundary value problem of partial differential equations. Two sets of non-homogeneous linear equations with 16 unknowns are constructed. By solving the equations, the expressions for the real bi-material elastic constant εt and the real stress singularity exponents λt are obtained with the bi-material engineering parameters satisfying certain conditions. By the uniqueness theorem of limit,undetermined coefficients are determined, and thus the bi-material stress intensity factor in mixed cracks is obtained. The bi-material stress intensity factor characterizes features of mixed cracks. When orthotropic bi-materials are of the same material, the degenerate solution to the stress intensity factor in mixed bi-material interface cracks is in complete agreement with the present classic conclusion. The relationship between the bi-material stress intensity factor and the ratio of bi-material shear modulus and the relationship between the bi-material stress intensity factor and the ratio of bi-material Young's modulus are given in the numerical analysis. 相似文献