河道淤泥气泡混合轻质土剪切流变特性及模型

利用剪切流变试验对以水泥为固化剂的河道淤泥气泡混合轻质土的流变特性进行了试验研究。试验结果表明,经固化处理的河道淤泥气泡混合轻质土在荷载作用下具有类似于硬粘性土的流变特征。剪切流变可以分为3个阶段：在剪应力水平较低时,剪切流变曲线呈衰减稳定型;随着剪应力水平的提高,剪切流变曲线呈非稳定的等速型;当剪应力水平增大到一定程度时,剪切流变曲线呈加速型。河道淤泥气泡混合轻质土的流变性随着混合轻质土强度的提高而降低。根据试验所呈现的剪切流变规律,可以发现河道淤泥气泡混合轻质土的剪切流变符合七元件黏弹塑性剪切流变模型,模型能够比较好地描述河道淤泥混合轻质土在各种剪应力水平下的衰减、等速以及加速流变过程。     

黏土的一维非平行等效时间线流变模型

在连续介质流变理论框架内研究了等效时间与流变速率之间的内在关系.当软土的流变速率仅取决于应力和应变量时,在相同应力和应变状态下简单加荷历史的黏土流变速率等于复杂加荷历史的流变速率,故根据简单加荷历史反算而得的黏土流变速率可用于复杂加荷历史的建模工作,在简单加荷历史下反算黏土流变速率所用的持续时间即是等效时间,在简单加荷历史簇中相同等效时间的应力应变关系线即为等效时间线.根据上述建模思路,获得了软土等效时间线不平行时流变速率与等效时间之间的关系,建立了等效时间线不平行时黏土的一维流变模型,该流变模型可退化为等效时间线平行时的Yin Graham一维流变模型.根据室内流变试验确定了模型参数并验证了模型的合理性.     

SBS改性沥青流变特性的研究

本文采用薄片剪切流变仪研究了 SBS 改性沥青的流变特性。结果表明:经 SBS 改性的沥青,其流变模型由 Burgers 模型(四元件模型)转变为更为复杂的五元件模型,其瞬时弹性和推迟弹性均匀明显增大,而粘性显著减少。     

建筑施工安全事故流变过程

为认知建筑施工过程中安全事故的形成过程,利用流变理论的基本原理,研究建筑施工安全事故的单流变模式和多流变模式的发展过程,给出两类流变模式的各阶段变化规律.提出安全事故流变强度的概念,利用故障树分析原理,给出流变强度的计算方法,并分析多流变模式下不安全事件对流变强度的结构敏感性和概率敏感性,为提高建筑施工安全管理效率和水...     

软土流变特性试验研究

根据室内三轴流变试验的结果,研究了北京地区粉质粘土的流变特性。结果表明,该类软土具有较明显的变形时效性及其在不同应力水平下的蠕变特性。通过分析蠕变曲线的规律,选择了广义开尔文五单元理论模型和时间硬化经验蠕变公式来描述软土的流变特性,并达到了良好的精度,建立了适合北京地区典型软土的流变理论模型和经验模型。     

Rheological constitutive model of rock mass based on viscoplastic theory

With many major projects under construction,more and more attention is paid to rheological mechanical properties of rock mass,and extensive researches are carried out for rheological constitutive modeling of rock mass.Based on viscoplastic theory,a new rheological constitutive model is proposed.The rationality and validity of proposed model are verified through the creep test data.The results show that the rheological constitutive model based on viscoplastic theory is able to simulate the typical creep curves of rock mass and the identified parameters are reasonable.Therefore,the rheological constitutive model could be used to describe the rheological mechanical behaviour of rock mass.     

阴离子型微乳液的流变性

对正十六烷、油酸钾、正己醇和水所形成的微乳液进行了研究，并对其流变性和机理作了探讨。结果表明：微乳液的粘度与水油比变化的机理可以用相转化来说明，即：以水为内相的球形→水的柱形→层状→油的柱形→水为外相的球形。层状结构区显示出有高粘度和异常流变性的特征，对此进行了讨论。     

Rheological characteristics of soft rock structural surface

There are two mechanisms of the coarse surface asperity resistance effect and rubbing resistance effect in the course of the soft rock structural surface creep,of which the former plays a dominant role in hindering the deformation in the starting creep phase,so that the structural surface creep usually displays the strong surface roughness effect,and so does the latter when the asperities in the coarse surface were fractured by shearing.Under the low stress condition,there are only two phases of the decelerating creep and the constant creep for the soft rock structural surface,and as the stress increases and overcomes the rubbing resistance,the accelerating creep failure of the structural surface will happen suddenly.Therefore,a multiple rheological model,which combines the nonlinear NEWTON body(NN) of a certain mass and the empirical plastic body(EM) with the classical SAINT VENANT body,NEWTON body,KELVIN body and HOOKE body,could be used to comprehensively describe the creep characteristics of the soft rock structural surface.Its mechanical parameter values will vary owing to the different surface roughness of the structural surface.The parameters of GH,GK and ηL are positively linearly correlative to the surface roughness.The surface roughness and m are negative exponential function correlation.The long-term strength τS is positively correlative to the surface roughness.     

似膏体粘弹塑性流变模型与流变方程研究

以浆体流变力学，粘弹性力学为基础，通过对似膏体充填料浆的微观结构分析。建立了其广义粘弹塑性流变模型。推导出流变方程的一般表达式；通过稳态和动态剪切条件下流变特性和流变参数的测试，得出了似膏体充填料浆的流变方程，研究结果为浆体输送的管路设计，阻力计算和参数优化等提供了理论依据。也为似膏体和其它高浓度（质量分数）浆体输送的管道损坏，机理以及解决措施的研究提供了新思路和新方法。     

苹果汁及其浓缩物的流变特性

本文对浓度为71°Brix的去果胶苹果汁在不同温度下的粘度及温度和浓度对粘度的影响进行了研究,给出了粘度随温度和随浓度变化的函数式以及温度和浓度对粘度的综合方程式,指出去果胶苹果汁在所给定的温度和浓度范围内属牛顿型流体。     

Rheological properties of asphalt mixtures containing various fibers

Rheological characteristics of fiber-modified asphalt mixture were investigated.Cellulous fiber,polyester fiber and mineral fiber were used as additives for asphalt mixture,and the dosages were 0.3%,0.3%,0.4%,respectively.Dynamic modulus test using superpave simple performance tester(SPT) was adopted to study the dynamic modulus and phase angle for the control mixture and fiber-modified ones at various temperatures and frequencies.Test results show that the rheological properties can be improved significantly by the addition of various fibers.The dynamic modulus increases with the increase of frequency,and the phase angle decreases with the increase of frequency.When various fibers are used,the dynamic modulus increases and phase angle decreases at each frequency.This indicates that the stiffness and the elastic portion of fiber-modified asphalt mixtures can be enhanced when various fibers are used,which results in the change of viscoelastic properties of mixtures.The creep test results show that the total strain and the permanent strain of asphalt mixtures during load-unload cycle can be significantly reduced,which results in the improvement of resistance to permanent deformation for asphalt mixtures containing various fiber additives.The Burgers model can be employed effectively to illustrate the rheological properties of fiber modified asphalt mixtures.     

淀粉α化常压修饰技术研究Ⅱ.颗粒α化修饰淀粉糊特性研究

对颗粒α化修饰淀粉的糊流变学特性、热稳定性和冻融稳定性研究表明 ,颗粒α化修饰淀粉具有假塑性流体特性 ,具有良好的在高剪切条件下的稳定性 ,具有良好的热稳定性和冻融稳定性 .     

岩石结构流变分析

本文介绍了作者在现场进行的塑性流变岩层流变试验的结果。分析导出岩石结构的流变方程,并且进行了计算机分析.     

茅口灰岩单轴压缩条件下的流变特性试验研究

取重庆北碚车站隧道茅口灰岩,根据现场岩层覆盖厚度及其茅口灰岩容重,取单轴压缩应力为6 MPa,采用MTS815多功能岩石试验机对岩样进行24 h单轴压缩蠕变试验,得到岩石轴向应变-时间曲线。分析岩石应变-时间曲线,发现茅口灰岩具有弹性-弹粘性之流变特性,与Poyting-Thomson model相似。用Origin软件对流变试验数据用Poyting-Thomson model方程进行拟合,得到低应力下流变拟合曲线,该拟合曲线能较好反应试验数据。因此,Poyting-Thomson model能较好反应茅口灰岩流变特性。最后求出了茅口灰岩低应力作用下流变模型各项参数。     

甲壳素溶液的流变性质及其可纺性

用旋转粘度计测量了不同浓度的甲壳素溶液的流动曲线 ,分析了CS2 体积分数、温度对流变性质的影响。研究表明 :各种浓度的甲壳素溶液的非牛顿指数n均小于 1,是切力变稀型流体。CS2 最佳体积分数为 2 %。为改善可纺性 ,需调整纺丝成型条件     

甲壳素溶液的流变性质及其可纺性

用旋转粘度计测量了不同浓度的甲壳素溶液的流动曲线,分析了CS2体积分数、温度对流变性质的影响。研究表明：各种浓度的甲壳素溶液的非牛顿指数n均小于1,是切力变稀型流体。CS2最佳体积分数为2%。为改善可纺性,需调整纺丝成型条件。     

Rheological behavior of basalt fiber reinforced asphalt mastic

The characters of basalt fiber are analyzed and compared with commonly used fibers. The rheological behaviors of the basalt fiber reinforced asphalt mastic are investigated by the dynamic shear rheological tests and the repeated creep tests. The results show that basalt fiber has excellent reinforced performances, such as high asphalt absorption ratio, low water absorption ratio, high tensile strength, high elastic modulus and high temperature stability. The rutting factor of the fiber reinforced asphalt mastic is higher than the plain asphalt mastic and the reinforced effects are more remarkable under high temperature. The rheological performances of the asphalt mastic demonstrate a good linear relationship between different temperature and loading frequency. The creep stiffness modulus of the asphalt mastic at different loading time can be expressed by power function. Improved Burgers model is used to represent the rheological behaviors of the asphalt mastic with basalt fiber and the model parameters are estimated.     

宁波软土流变试验及经验模型

为了研究宁波软土的流变特性及经验模型,进行一维固结流变试验和三轴排水流变试验,并采用西原模型拟合模型参数.试验对比分析表明,固结试验的侧限作用会阻碍试样流变的发展,应力-应变等时曲线偏向应力轴,而三轴流变试验试样的流变能够得到充分地发展,应力-应变等时曲线偏向应变轴,能够更好地体现软黏土的流变性状.将一维西原模型应力-应变关系扩展到三维,采用修正剑桥模型屈服函数描述材料的塑性屈服.推导荷载恒定时土样的轴向应变计算公式,根据三轴排水流变试验结果进行曲线拟合,确定西原模型参数.结果表明,该模型能够较好地符合宁波软土的流变规律.     

农业物料流变特性的控制论方法研究

对农业物料流变特性控制论方法研究的有关问题进行探讨，首先提出了阻抗方法系统建模与分析，构建一种流变－电相似关系，为物料流变特性的电模拟实验提供了理论依据。     

面团吹泡特性与拉伸特性的比较研究

研究了吹泡示功仪和拉伸仪在检测面团流变学特性时的相关性.结果表明:两种小麦L值与拉伸阻力相关系数分别为0.744、0.752,具有显著相关性；W与拉伸比的相关系数为0.799、0.808,具有显著相关性;L与最大拉伸阻力的相关系数为-0.634、-0.634,具有显著负相关.