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The external nonstationary load acting on an electroelastic bimorph (metal–piezoceramics) beam with split conductive coatings is identified. Use is made of the Laplace transform. The original functions are recovered analytically. The unknown quantities are determined by solving a system of Volterra equations 相似文献
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The dynamic coupled thermoelastic problem formulation and the thermodynamically consistent theory of inelastic behavior of
materials are used to solve an axisymmetric problem for a steel disk subject to a heat pulse at the center. The temperature
dependence of the physical and mechanical properties of the disk is taken into account. The problem is solved by the FEM.
The evolution in time and features of the strain-stress and thermal states of the disk and the dynamic effects accompanying
the processes of heating and gradual cooling are studied
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Translated from Prikladnaya Mekhanika, Vol. 44, No. 5, pp. 45–57, May 2008. 相似文献
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硬盘驱动器冲击激励的头盘碰撞分析 总被引:3,自引:0,他引:3
根据Winchester型硬盘驱动器在冲击载荷作用下头盘碰撞的动力学方程,利用数值模拟方法分析了在正弦半波激励条件下头盘系统的动力学响应过程。当头盘系统发生碰撞时,冲击激励峰值加速度与作用时间的倒数之间具有近似线性关系。随激励强度和作用时间的变化,硬盘驱动器具有性能退化、盘面局部损坏和头盘系统结构破坏三种失效形式。磁头浮动块与磁盘盘面发生多次碰撞,碰撞位置可能在浮动块尾端,也可能在浮动块的前端。硬盘驱动器冲击失效的理论分析结果得到了爆炸冲击环境条件下试验现象的验证。 相似文献
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为了分析冲击荷载作用下粘土的孔隙水压力的增长规律,为分析粘土介质的动态响应、动力固结加固提供理论依据,将冲击瞬态荷载简化为三角形荷载,通过编制瞬变动态弹塑性有限元程序,对冲击荷载作用下粘土孔隙水压的动态响应进行了模拟,得出了冲击荷载作用下粘土孔隙水压的增长规律,发现孔隙水压力峰值无论是随水平距离还是随深度的增加均呈指数形式衰减,和实际工程施工中孔隙水压的监测数据相吻合。 相似文献
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冲击载荷下导线覆冰脱落过程的数值模拟 总被引:2,自引:0,他引:2
采用ABAQUS有限元软件建立输电线路有限元模型,模拟研究单档覆冰导线在冲击载荷作用下的除冰过程。覆冰破坏采用拉伸破坏准则,利用ABAQUS的用户材料子程序VUMAT,定义覆冰的本构关系并实现覆冰破坏单元删除的判定。进一步模拟研究在不同冲击载荷幅值、线路档距和覆冰厚度等条件下的除冰率,结果表明:除冰率随冲击载荷幅值的增加而增大;覆冰厚度和档距越小,除冰率越大;连续档线路需要更大的冲击载荷才能达到较好的除冰效果。所得结果可以为机械式除冰装置的设计提供参考。 相似文献
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《International Journal of Solids and Structures》2005,42(16-17):4541-4554
The scattering problem for a single ellipsoidal piezoelectric inclusion embedded in piezoelectric medium is investigated. Based on the polarization method, the extended displacements are expressed in terms of integral equations, whose kernels are obtained from the Green’s functions of homogenous matrix. In this paper, the 3D dynamic Green’s functions are derived by means of the Radon transform technique. To illustrate the use of the equations, scattering by a piezoelectric, ellipsoidal inhomogeneity in a piezoelectric medium is considered in the low frequency and an asymptotic formula for this scattering cross-section is obtained. Numerical results of the scattering cross-sections are carried out for a spheroidal BaTiO3-inclusion in a PZT-5H-matrix. 相似文献
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G. A. Al'ev 《Fluid Dynamics》1990,25(1):160-162
A study is made of the three-dimensional problem of the interaction between a disk that enters water asymmetrically and a shock wave that is moving toward the disk. The water is assumed to be a perfect compressible liquid and the flow adiabatic. The changes in the flow parameters and the state are determined by numerical integration of the equations that describe the flow. A three-dimensional version of the finite-difference scheme of [1] is used in accordance with the method of [2]. The influence of the intensity of the shock wave on the drag coefficient of the disk and the shape of the free surface is investigated.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 1, pp. 185–187, January–February, 1990. 相似文献
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Unsteady processes in a cylindrical shell with an elastic medium under the influence of a shock load
International Applied Mechanics - 相似文献
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IntroductionTheinteractionofdislocationswithinclusionsisofconsiderableimportanceforunderstandingthephysicalbehaviorofmaterials.Suchstudiescanprovidedinformationconcerningcertainstrengtheningorhardeningmechanismsinnumberoftraditionalandcompositemateri… 相似文献
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M. P. Malezhik I. S. Chernyshenko G. P. Sheremet 《International Applied Mechanics》2006,42(8):948-950
The stress wave field around a tunnel in an anisotropic medium subject to shock load is analyzed using the dynamic photoelastic
method. The influence of various factors on the distribution and magnitude of boundary stresses around the tunnel are studied
by simulating the deformation process. The time dependence of the dynamic stress concentration factor on the tunnel walls
is established
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Translated from Prikladnaya Mekhanika, Vol. 42, No. 8, pp. 122–125, August 2006. 相似文献
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A. O. Vatul'yan N. B. Lapitseaya A. V. Nas dein A. S. Sealiue A. N. Solov' 《Journal of Applied Mechanics and Technical Physics》1995,36(4):594-598
Rostov State University. Rostov State Technical University, Rostov-on-Don 344000. Translated from Prikladnaya Mekhanika i
Tekhnicheskaya Fizika, Vol. 36, No. 4, pp. 131–136, July–August, 1995. 相似文献
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Dr. S. Yano Prof. Dr. T. Kotera 《Archive of Applied Mechanics (Ingenieur Archiv)》1991,61(6-7):373-381
Summary Vibrations of a rotating disk with a clamped inner circle, a free outer periphery and an elastic support at one point are analyzed under the action of a static in-plane load. A solution of the equation of motion is described in form of series by orthogonal eigenfunctions of a non-rotating disk with the same boundary conditions. Relations between natural frequencies and angular velocity and then those between regions of instability of vibrations and the magnitude of static load are shown.
Instabilität einer drehenden Scheibe mit einer Stütze unter der Wirkung einer ebenen statischen Belastung
Übersicht Schwingungen einer drehenden Scheibe mit einem befestigten inneren Umfang, einem freien äußeren Umfang und einer elastischen Stütze in einem Punkt werden unter der Wirkung einer ebenen statischen Belastung analysiert. Eine Lösung der Bewegungsgleichung wird in der Form von Reihen mit orthogonalen Eigenfunktionen einer nicht drehenden Scheibe mit den gleichen Randbedingungen beschrieben. Beziehungen zwischen Eigenfrequenzen und der Drehgeschwindigkeit sowie zwischen instabilen Bereichen und der Größe der statischen Belastung werden gezeigt.相似文献