| 1. | The development of shear band was researched by analyzing the confining pressure - time history , volumetric curve and displacement field of pfc model 通过分析围压时步曲线、体变曲线和不同阶段的颗粒位移场的变化规律,研究了剪切带的形成与发展规律。 |
| 2. | To generate a forecast , a numerical weather prediction model repeatedly advances the model state from one instant through a small time step ( a few seconds to a few minutes depending on the scales of motion resolved by the model ) 在执行预报时,数值天气预报模式会从某一瞬间时刻以微小的时步,重复向前计算模式的状态(时步可由几秒到几分,视模式所解析的运动尺度而定) 。 |
| 3. | It calculates the effects during each time step of winds carrying along the various atmospheric properties and of the processes of evaporation , rainfall , surface friction , infrared cooling and solar heating that occur in the area of interest 在每个时步里,模式计算的作用包括:各种随著风改变的大气性质、蒸发过程、降水、表面摩擦以及在重要地区的长波辐射冷却与日照加热。 |
| 4. | Concrete elastic modulus and concrete creep and shrinkage variety at different time are reckoned in by using time increment analysis method and concrete creep and shrinkage secondary force is calculated by using effective elastic modulus . bridge stability analysis program is developed on the base of structure matrix displacement method , the program adopts visual basic language , has friendly interface and visual data input windows . the buckling safety factor of currently finished structure is given as result 为计入混凝土弹性模量的变化及混凝土徐变收缩随混凝土的龄期与外荷载加载时间不同而变化的影响,采用时间增量法对每个计算阶段根据其阶段内时步数进行循环,以计算时段内弹性应力、应变增量和徐变、收缩产生的应力应变增量,利用有效弹性模量法计算混凝土徐变收缩次内力,在此基础上,结合结构矩阵位移法的基本理论编制开发了计入混凝土时效效应的高墩大跨径桥梁稳定分析程序。 |
| 5. | The rule about water flow in the unsaturated soil and the soil - water characteristic curve are described in this thesis in the first time step during the numerical simulation , the permeability coefficient is calculated according to the initial water content of the unsaturated soil , because of as shown in the soil - water characteristic curve has the hysteresis phenomenon 阐述了非饱和土中水流动的基本规律和土水特征曲线。由于土水特征曲线具有滞后的特点,提出了根据初始含水量来确定数值模拟初始时步非饱和土的渗透系数。 |
| 6. | The characteristics of stress and displacement in tunnel surrounding rocks are studied . the change feature of the stress in surrounding rocks and the variations of stress and the displacement of prop structure in different excavation step are analyzed with 3 dimensional fem . finally , the construction method is proved to be reasonable and scientific 通过三维有限元计算研究了隧道围岩的应力、位移特征,分析了隧道围岩不同开挖时步的应力变化特点以及支护结构的应力与位移的变化特征,进而论证了该施工方法的合理性和科学性。 |
| 7. | ( 5 ) conclusion was obtained by the analyzing and studying the mechanics environment of the rock mass and the landslide on right bank : according to the analysis , the present direction of the maximal principle stress was consistent with the present tectonic stress field , the value of the principle stress increased or reduced in special place , and there was tensile stress region at the 2000m or above it on the left bank , the accumulate and adjustment was very limited in 200 years , the calculated result of the landslide indicated that the landslide on the right bank was stable under the various conditions ( 5 )坝址区河谷岩体力学环境及右岸古滑坡体的稳定问题分析得出:河谷岩体应力场的分析显示,河谷岩体中主应力的方向基本上与现今区域构造应力场的方向一致,在一些特殊地带岩体的主应力值有所降低或增高,特别是在左岸的2000m高程附近及以上,存在有明显张应力区。在未来200年流变计算时步范围内,河谷岩体应力的积累与调整较为有限。同时对滑坡体各种工况条件下的稳定性计算结果表明,右岸古滑坡体在各种工况条件下是处于稳定状态的。 |
| 8. | On the aspect of the dynamic character , the electrocircuit model of the motor is being realized on the pspice environment . the transient character of the pmlsm under the sinusoidal power is reached using the pspice model at circuit level , the results are compared with those using time - stepping fem 从电机的动态性能方面:建立了电机的pspice模型,在pspice环境下对电机进行正弦波驱动下瞬态特性的仿真,并与以电磁场分析为基础的时步有限元电机的动态仿真分析进行了比较。 |
| 9. | Finally a set of equations with initiate values for boundary value problem is established where the velocity potential and its normal derivative are unknowns . because the model includes the effects of both the time and space to the velocity potential of free surface , it can be applied to strong nonlinear wave . as examples , solitary wave is computed in the numerical flume 推导给出计算域内以所有节点波势函数和波面位置高度的时间增量为未知量的线性方程组,并同时考虑时间因素和空间变位对波面势函数的影响,在预设的计算精度下,通过时步内的循环迭代逐一确定每个时步上的波面运动位置,从而建立了一种可适于求解强非线性波浪变形计算的数值模式。 |
| 10. | Based on this , the traditional model of time series analysis and gray system theory that is developed recently are established to forecast . and an exploring is carried out applying the function of step that the 3d - flac software offered . this will provide material of dynamic and timely landslide forecast for engineering practice and scientific research 在此基础上,本文运用传统的时间序列分析方法和近年来发展起来的灰色系统理论建立了预测模型;并利用3d - flac软件提供的时步( step )功能在研究库岸滑坡的动态预报上做了探索。 |