共查询到17条相似文献,搜索用时 826 毫秒
1.
弹性波垂直于压电材料摩擦接触界面入射会引起界面局部滑移或分离,导致问题具有边界非线性。应用傅里叶分析技术将问题的求解转化为一组代数方程,通过迭代-修正的方法确定粘着、滑移、分离区的分布位置,给出了各种状态产生的条件及规律。由于边界非线性导致波形畸变并诱发高频谐波,对某些各向异性压电材料,在某些条件下单一入射波遇到界面产生再极化,导致耦合P波及SV波产生,文中给出了高频谐波解及波形极化的产生条件。外加荷载和外加电场通过机电耦合效应对界面产生影响,通过实例分析,给出了外加作用力和电场对一般各向异性材料的影响规律,并分析了因为材料常数不同而引起的影响规律的不同。 相似文献
2.
弹性波与压电材料接触界面的相互作用问题是工程应用中常见而复杂的问题,入射波足够强会引起界面出现滑移和分离,但滑移和分离的边界未知,边界条件具有非线性特性。通过Fourier分析,将混合边值问题的求解转化为非线性代数方程,利用软件通过迭代修正的方法进行了求解;给出3种状态边界的求解,分析入射波强度、外加应力及电场对界面状态的影响,并对高频谐波的特性进行分析,通过实例对理论推导进行验证,结果显示:入射波强度、外加荷载和电场的大小及摩擦因数均会影响到界面,通过改变这些条件可以控制界面状态,另外检测高频谐波的信号也可以反映界面状态。 相似文献
3.
4.
5.
6.
一般各向异性单侧接触界面上波的反射和折射 总被引:7,自引:0,他引:7
研究简谐弹性波在一般各向异性介质单侧接触界面上的反射和折射问题.利用Fouier分析方法将非线性Coulomb摩擦接触边界波动问题化为一组代数方程.给出了确定局部分离、滑移和粘着区的思路和方法及各区域的解;讨论了出现界面局部分离和滑移的条件.对特定材料组合情况进行了详细数值计算,给出了界面力、相对滑移速度、张开位移、高频谐波的反射折射系数等特征参量;考察了平面和反平面波动的耦合及整体滑移等.其中关于高频谐波的结果可对已有实验结果给出很好的定性解释.在大多数情况下,即使对摩擦系数无穷大的粘滞接触界面,分离区端部也总是存在一个很小的滑移区。 相似文献
7.
利用Stroh公式,Fourier分析和奇异积分方程技术研究了两各向异性弹性半空间光滑接触可分离界面上滑移脉冲波的存在及其传播特性。结果表明,如果至少能在一种介质中存在Rayleigh波,且其波速小于两种介质中的最小极限速度,则滑移脉冲波就可以存在。这种脉冲波传播速度不确定,可在最小极限波速与较低的Rayleigh波速之间取值,而该取值范围又取决于无界面分离情况下的第一、第二滑移波的解。分离区大小取决于扰动的强度,界面法向力和质点速度在分离区两端有 1 /2奇异性。 相似文献
8.
9.
粘塑性流体的界面滑移对润滑性能的影响研究 总被引:3,自引:0,他引:3
首先指出经典润滑理论中的边界无滑移条件已不再适用于具有极限剪应力的粘塑性流体润滑.而后,通过确定最大剪应力位置和加入剪应力边界条件,建立了界面滑移后的润滑方程.在联立求解不同区域的润滑方程基础上,对界面滑移的开始位置及扩展方式进行了分析.最后,讨论了不同膜厚比下滑移对润滑性能的影响. 相似文献
10.
金属成形加工中润滑界面滑移分析是工程技术人员普遍关注的重要课题之一。因此,利用有限元及参数二次规划法分析研究了金属轧制过程入口区的界面滑移问题。结果发现,滑移速度可用参数二次规划技术直接获得,在压力分布和滑移速度之间不存在迭代过程;界面滑移可以使润滑油膜厚度明显减小,这与文献报道的试验结果一致;粘塑性润滑剂的初始极限剪应力和极限比例常是面滑移的影响很大。从而影响了油膜厚度;当润滑剂和工件材料及厚度 相似文献
11.
Transmission of elastic waves through a micro gap between two solids with consideration of frictional contact is investigated.By using the Fourier analysis technique and the corrective solution method,the nonlinear boundary problem is reduced to a set of algebraic equations.Numerical results exhibit the locations and extents of separation, slip,and stick zones,the interface tractions,and the energy partition.The effects of gap width,frictional coefficients,and the incident angle on the wave transmission ... 相似文献
12.
FengYangde WangYuesheng ZhangZimao CuiJunzhi 《Acta Mechanica Solida Sinica》2003,16(3):189-196
A 2D time domain boundary element method (BEM) is developed to solve the transient scattering of plane waves by a unilaterally frictionally constrained inclusion. Coulomb friction is assumed along the contact interface. The incident wave is assumed strong enough so that localized slip and separation take place along the interface. The present problem is in effect a nonlinear boundary value problem since the mixed boundary conditions involve unknown intervals (slip, separation and stick regions). In order to determine the unknown intervals, an iterative technique is developed. As an example, we consider the scattering of a circular cylinder embeddedin an infinite solid. 相似文献
13.
《International Journal of Solids and Structures》1999,36(30):4563-4586
This is Part II of a two-part paper which analyses the re-polarization of elastic waves at a frictional contact interface between two solids. The re-polarization of SH waves was solved in Part I by the use of the Fourier analysis. Here, in Part II, we consider the re-polarization of P or SV waves. It is assumed that the two solids are pressed together and, at the same time, loaded by anti-plane and in-plane shearing traction. If the incident wave is sufficiently strong, localized separation and slip may take place at the interface. As a result, the incident in-plane wave is re-polarized at the interface so that the anti-plane waves (SH waves) are induced. Using the method similar to that of Part I and considering the boundary conditions involving separation and slip, we manage to reduce the problem to a set of algebraic equations coupled with simple integral equations. An iterative method is developed based on the solution to the perfectly bonded interface. The locations and sizes of the separation and slip zones, the interface traction, the slip velocities, the global sliding velocities and the energy dissipation and partition are displayed for the case of two identical materials. It is found that the separation zones and the gaps are independent of the induced waves. 相似文献
14.
15.
Slip pulse along an interface between two anisotropic elastic half-spaces in sliding contact with separation 总被引:2,自引:0,他引:2
The Stroh sextic formalism, together with Fourier analysis and the singular integral equation technique, is used to study
the propagation of a possible slip pulse in the presence of local separation at the interface between two contact anisotropic
solids. The existence of such a pulse is discussed in detail. It is found that the pulse may exist if at least one medium
admits Rayleigh wave below the minimum limiting speed of the two media. The pulse-propagating speed is not fixed; it can be
of any value in some regions between the lower Rayleigh wave speed and minimum limiting speed. These speed regions depend
on the existence of the first and second slip-wave solutions without interfacial separation studied by Barnett, Gavazza and
Lothe (Proc. R. Soc. Lond. 1988, A415, 389–419). The pulse has no free amplitude directly but involves the arbitrary size
of the separation zone that depends on the intensity of the motion. The interface normal traction and the particle velocities
involve a square-root singularity at both ends of the separation zones that act as energy source and sink. 相似文献
16.
R.J.H. Paynter D.A. Hills D. Dini 《International Journal of Solids and Structures》2010,47(18-19):2613-2619
The edge of a complete contact between elastically similar bodies may often be modelled as a semi-infinite monolithic wedge, because, under a wide range of conditions, the interface is often fully closed and stuck or has small regions of lift and slip at the contact edge. When the local edge separates from the half-plane and slip is inevitable a correction to the Williams solution is required, and this is deduced for the case where the contact-defining body possesses a 90° corner. A simple application of the solution to the example problem of a clamped strip subject to tension is calibrated and the results found used to infer the slip and separation lengths. 相似文献
17.
《European Journal of Mechanics - A/Solids》2003,22(1):107-118
The dynamical problem of a brake-like mechanical system composed of an elastic cylindrical tube with Coulomb's friction in contact with a rigid and rotating cylinder is considered. This model problem enables us to give an example of non-trivial periodic solutions in the form of stick–slip or stick–slip–separation waves propagating on the contact surface. A semi-analytical analysis of stick–slip waves is obtained when the system of governing equations is reduced by condensation to a simpler system involving only the contact displacements. This reduced system, of only one space variable in addition to time, can be solved almost analytically and gives some interesting informations on the existence and the characteristics of stick–slip waves such as the wave numbers on the circumference, stick and slip proportions, wave celerities, tangential and normal forces. It is shown in particular that the stick–slip–separation solutions would occur for small normal pressures or high rotational speeds. Since the analytical discussion becomes cumbersome in this case, a second approach based on numerical analysis by the finite element method is performed. The existence and the characteristics of stick–slip and stick–slip–separation waves are discussed numerically. 相似文献