应力张量

Following the constraint of AMFI on the SGS stress model, a non-linear SGS stress model is developed, based on the tensor algebra and Taylor expansion theory, in terms of resolvable strain rate tensor and rotation tensor.

根据旋转湍流SGS模型的建模规则，利用张量代数和Taylor近似理论发展了一种由大涡应变率和旋转张量构成的非线性SGS应力模型，并满足AMFI条件。

Based on the theory of matrix, this paper focuses on the similarity of stress tensor in different coordinate systems and then an instance performed by Ansys and Matlab is given to validate this conclusion.

以矩阵论的相关理论为依据，论证在不同的坐标系下，应力张量满足相似变换的特性；并通过Ansys有限元分析软件与Matlab数值计算软件构建实验平台对此加以验证。

Plugged the resulting stress tensor into the momentum equations and its divergence resulted in the production of the Navier-Stokes equations.

向动量方程中引入作为结果的应力张量，并且它的散度产生了Navier-Stokes方程。

The electrostatic force evaluation with Maxwell stress tensor theory properly explains the experimental results.

采用Maxwell应力张量对微粒受到的静电力进行了计算和分析，其结果从力学角度解释了实验观察得到的结果。

The results shows that die pressure of extruder, relaxation time of polymer and geometrical parameters of die have significant effect on stress tensor in extruder die. By changing the geometrical parameters in the flowing channel, the pressure can be controlled.

模拟结果表明：机头压力、材料的松弛时间以及口模流道的几何尺寸对高聚物在机头中的应力张量的变化影响较大；通过改变挤出流道的几何尺寸，完全可以控制高聚物的熔体压力。

In order to independence establish CFD software, this paper derives Navier-Stokes equations on non-inertial system and Favre-averaged equations, and Reynolds stress tensor on the basis of fluid mechanical fundamental.

为了独立编制CFD软件，本文从流体力学的基本原理出发，推导了非惯性系下Navier-Stokes方程组和Favre平均的方程组，同时对雷诺应力张量进行推导。

In view of the non-linear relation between the hefts of the partial stress tensor and the velocity gradient of the fluid, the intrinsic equation only depends on the first order differential coefficient of the velocity gradient.

考虑流体的偏应力张量分量与速度梯度为非线性关系的情况，本构方程仅依赖于速度梯度的一阶导数。

This article mainly simulates gradually damage destruction process of rock, major in determinationg the definition of rock three-dimensional damage tensor, simplify to the damage tensor and obtain its engineering calculation method, and obtains the basic expression form of equivalent stress by equivalent stress assumption, symmetrization to the actual stress, thus obtains construction relation of the festival principle of three-dimensional damage rock mass, finally couples elasticity- plasticity with damage in the finite element equation, with reference to elasticity-plasticity gradually degenerated method thought, simulates rock damage to advance gradually the destruction process in finite element method, draws up elasticity - plasticity and damage coupling two-dimension finite element procedure with the C language in the VC contact surface, by simulating experiment destroyed process, acquires destruction image and the axial load distortion curve of model, agreement with the experimental result.

本文主要模拟岩石渐进损伤破坏过程，确定岩石三维损伤张量的定义，对损伤张量进行简化计算并得出其工程计算方法，采用等效应力假设得出有效应力的基本表达形式，对有效应力进行对称化，得出节理损伤岩体的三维本构关系，在有限元方程中实现弹塑性和损伤耦合；借鉴弹塑性渐进退化方法的思想，采用有限元的方法模拟岩石损伤渐进破坏过程，用C++语言在VC界面编制了弹塑性和损伤耦合的二维有限元程序，通过模拟已有的实验破坏过程，得出模型的破坏图像和轴向荷载变形曲线，与实验结果基本一致。

The result shows that the Lighthill stress tensors in the make flows could generate sound field in the far field.

结果表明，尾迹流中的Lighthill应力张量能在远场产生声场。

The Lighthill stress tensors in the wake flows could generate sound field in the far field.

尾迹流中的Lighthill应力张量能在远场产生声场。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。