虚拟力

The settlement regularity of particle under non-linear drag force, Basset force and virtual mass force is analysed.

分析了颗粒在液体中受到非线性曳力、Basset力以及虚拟质量力作用时的沉降规律。

By decomposing the problem system into an extended saturated soil system and a virtual pile system, through the strain compatibility condition between the extended saturated soil system and the virtual system at an arbitrary depth z along the pile, and combined the Laplace transform and its convolution, a Fredholm intergral equation of the second kind of the single pile in saturated layered transversely isotropic soils is established. The axial force and diaplacement of the pile are obtained by solving the Fredholm intergral equation.

将求解体系看作是饱和土体和虚拟桩的叠加，利用沿桩身任意一点z处饱和地基与虚拟桩的应变协调，并结合Laplace变换及其卷积性质，建立了饱和成层横观各向同性地基中竖向受荷单桩问题的第二类Fredhlom积分方程，对该积分方程进行求解可得桩的真实轴力、位移。

This paper designed a kind of biliary tract virtual surgery simulation system and discussed the actualization of related techniques such as system structure design, 3D reconstruction, collision detection, elastic deformations of soft tissues and force feedback.

设计了一种用于外科医生仿真训练的具有实时力反债的胆道虚拟手术仿真系统。主要讨论了本系统的结构设计、三维重建、碰撞检测、软组织的弹性变形和力反馈等方面的技术实现。

Changsha 410083, China）Abstract: Based on the stability analysis for slope with polygon elements, the equilibrium of elements was evaluated by adapting fictitious force acting at boundary of element to calculate factor of safety, the behavior of the fictitious force was studied while the factor of slope safety changes,the procedure was discussed to obtain the factor of slope safety in an iterative way if the adopt fictitious force was vanished finally.

摘 要：基于边坡稳定性分析的任意条分方法，在单元静力平衡分析中引进作用在边界上的虚拟平衡力，满足边坡安全系数求解过程中单元静力平衡的要求。

The testing system will only display the direction, magnitude and undulatory dynamic status of axial force accurately.

摘 要：用计算机仿真技术，通过抗热变形干扰的 LabVIEW 虚拟仪器轴向力测试系统，确定端盖压头应变片的抗热变形干扰粘贴位置，使轴向力测试系统动态显示轴向力的作用方向、大小、及其波动情况。

In the virtual surgery system, the virtual scalpel could be manipulated on 3D liver mould with PHANTOM. The simulating effect was the same as the clinic operation for auxiliary partial orthotopic liver transplantation. Plane visualization of hepatic resection and intrahepatic vessel cutting was achieved by adjusting the transparency of the resection part. Life-like could be felt and power feeling could be touched during virtul operation. Conclusion ① The visualized liver mould reconstructed is 3D and verisimilar, and it is helpful to design reasonable scheme for liver transplantation.

在建立的虚拟手术系统的虚拟环境中，使用力反馈设备PHANTOM操纵"虚拟手术刀"模拟了辅助性部分原位肝移植的手术过程，其结果符合临床手术的效果；通过控制肝脏模型切除部分的透明度，使肝脏手术切割平面可视化以及肝脏内部管道手术切断平面可视化；手术模拟过程逼真，形象，且有"力"的感受。

After reviewing some research results of the human hand haptics, a measuring apparatus was constructed to measure the human fingers' contact force and contact areas. Then experiments were performed on in-vivo fingertips. From the experimental data, a contact force model was deduced to describe the real contact force properties of human fingertips.

通过分析虚拟环境中几种重要的接触力生成算法，结合人手的感知特性，构建了人手指接触力测量平台，研究了手指接触力和接触面积之间的关系，提炼出以接触面积为变量的指尖接触力的力学模型。

Based on force feedback device named PHANTOM produced by SensAble Inc.,this system makes use of virtual reality technology to implement the surgery procedures of liver and tissue.

该系统基于SensAble公司的PHANTOM力反馈设备，利用虚拟现实技术实现肝脏手术过程中有关肝脏及其内部组织的多种手术操作，提供真实的视觉反馈和力反馈，其有良好的实时性。

Geometrical and physical parameters of components of the absorber in the virtual prototype follow from those technical data of a specific passenger car. Bench tests are conducted and a series of experimental results have been obtained by the MTS absorber test machine for the damping force-velocity which can be imposed in the virtual prototype for dynamic simulation. The piecewise, the hysteretic looped and the abnormal looped hysteretic force-velocity curves for the absorbers are, respectively, input into the prototype.

减振器阻尼力—速度特性是根据MTS减振器特性试验机试验结果，通过分段拟合，分别以分段线性、迟滞环和迟滞环畸变情况输入虚拟样机进行仿真分析，试验及仿真结果比较说明：减振器速度外特性采用迟滞环非线性，比采用双线性化模型更接近试验结果，能够更合理地解释试验现象；减振器阻尼力速度特性曲线出现畸变，如在复原行程初期迟滞特性曲线出现交叉现象，可以引发减振器系统动力特性的高频振动成分增加。

Base on the relationship of the gauge control system and the shape open loop control, it is proved that AGC has a rather large effect on plate shape but less contribution on gauge precision when the plate is wide and thin.

该方法通过定义一个虚拟最大轧制力限制系数来调节各道次轧制力，使得最后三个道次轧制力线性下降，满足板形控制的要求，而前面道次尽量发挥轧机的能力采取大压下量。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。