树脂硫化剂对丁基橡胶硫化胶阻尼行为的影响

研究了树脂硫化剂硫化丁基橡胶材料的阻尼性能，同时对相应的阻尼机理进行了研究，以期对这类阻尼材料的阻尼机制获得更深刻的认识和了解。     

Linear Stability of Flows in a Squeeze Film

We study linear stability of viscous flows in a squeeze lubrication film, in which the flow varies slowly in space and time, between two parallel plates moving normal to each other with a slow constant speed, generalizing the inviscid results of Aristov and Gitman [J. Fluid Mech. 464 (2002) 209]. The temporal evolution of twodimensional disturbances for this physical situation, including the asymptotic behaviour of a long term or the transient behaviour of some time interval, is obtained by the construction of a low-dimensional Galerkin method.It is found that the wall boundaries typically play dual roles of stabilizer and destabilizer. They constrain the development of disturbances and have stabilizing influences. However, they give rise to velocity shear, which is diffused by viscosity and thereby tends to destabilize the flow.     

一类具有非线性阻尼的梁系统的整体吸引子

利用经典的算子半群理论,研究了一类具有非线性阻尼和非线性外力项的梁方程的初边值问题,证明了系统解的存在唯一性,然后引入一个算子半群;利用经典的算子半群分解方法,证明了系统存在整体吸引子.     

一类具强阻尼Kirchhoff方程的能量衰减和解的爆破

The initial boundary value problem for a Kirchhoff equation with Lipschitz type continuous coefficient is studied on bounded domain. Under some conditions, the energy decaying and blow-up of solution are discussed. By refining method, the exponent decay estimates of the energy function and the estimates of the life span of blow-up solutions are given.     

圆柱箱体中液体晃动阻尼的数值研究

对于部分充液的圆柱箱体中液体晃动,自由液面对晃动阻尼的影响显著,特别当自由液面在挡板附近,流动更加复杂.为了更加准确地计算带挡板的部分充液圆柱箱体中液体晃动阻尼,采用基于有限体积法的VOF方法模拟箱体中带有自由液面的流体流动.自由液面的重构采用具有二阶精度的分段线性重构方法,界面通量计算采用一步算法,计算了不同充液高度均匀布置的三块半圆形挡板对液体晃动阻尼的影响,得到了阻尼比随液位的变化曲线,获得了该型式挡板的阻尼性能.     

CAUCHY PROBLEM OF ONE TYPE OF ATMOSPHERE EVOLUTION EQUATIONS

One type of evolution atmosphere equations was discussed. It is found that according to the stratification theory, （i） the inertial force has no influence on the criterion of the well-posed Cauchy problem; （ii） the compressibility plays no role on the well-posed condition of the Cauchy problem of the viscid atmosphere equations, but changes the well-posed condition of the viscid atmosphere equations; （iii） this type of atmosphere evolution equations is ill-posed on the hyperplane t = 0 in spite of its compressibility and viscosity; （iv） the Cauchy problem of compressible viscosity atmosphere with still initial motion is ill-posed.     

对二维分离流涡黏性系数非线性分布的新认识

以弱非线性涡黏性模型为出发点,对Delery分离流动实验结果进行分析并获得了非平衡态分离区涡黏性系数与形状因子J之间的非线性关系. 该非线性关系显示在分离起始阶段,涡黏性系数较平衡态先减小,后增大;再附阶段,涡黏性系数较平衡态数值逐渐增大,并在再附点位置接近最大,而后又逐渐减小,恢复到平衡态水平. 总结涡黏性系数的这种非线性发展数学关系式,并将它应用于BL模型,在不添加微分方程的情况下发展出一种适用于分离流动的改进代数湍流模型. 对低速平板流动,跨声速,超声速以及高超声速分离流动的计算结果表明,该改进湍流模型可以较准确地模拟各类复杂分离流动,计算精度明显优于传统代数模型以及一些两方程模型,而计算工作量仍与BL模型相当. 这表明所提出的涡黏性系数非线性发展规律是正确的,且应用在二维分离流动中具有一定的普适性.      

聚四氢呋喃/聚苯乙烯交联嵌段及接枝共聚物的合成与阻尼性能

合成接枝共聚物和嵌段共聚物是研究阻尼材料的重要途径,这是由于可以在较广的范围内,调整共聚物的结构,使之具有良好的阻尼性能。这里我们选择了端羟基聚四氢呋喃与顺丁烯二酸酐反应,制成端乙烯基大分子单体及端乙烯基遥爪低聚物。然后与苯乙烯共聚,制成接枝共聚物和嵌段共聚物。从两者的比较中探讨各种因素对共聚物阻尼性能的影响规律。认为研究结果将有益于阻尼材料的分子设计,在反应体系及合成方法上,都比较简便,适于工业生产,便于推广应用。     

酚氧树脂／蓖麻油交联聚氨酯

使2.2-(4’-羟基苯基)丙烷(双酚A)与环氧氯丙烷反应制得了带端羟基的酚氧树脂(HBA),将其与蓖麻油共混,用2.4-甲苯二异氰酸酯(TDI)作固化剂,制得了一系列交联聚氨酯。DSC和DMA测试结果表明,这种聚氨酯只有一个T_g。改变NCO/OH摩尔比及HBA/(HBA 蓖麻油)比可制得具有较好阻尼性能的聚氨酯材料。     

CIIR/PMAc IPNs阻尼性能

CIIR/PMAc IPNs阻尼性能;氯化丁基橡胶; 互贯聚合物网络; 聚(甲基)丙烯酸酯; 阻尼性能