It is presented that there is a critical speed which will make the trend of dynamic response change when the train passes through the transition section.

The method adopting average link speed overcomes the limitations of the present method using spot speed to track vehicular queue and employing objective calibrated critical speed identifies vehicular queue status based on spot data. Calculations of real examples show that this method may offer higher precision, although the model structure is relatively simple.

Two methods on sensitivity analysis for dynamic correction of AFV critical speed were suggested,i. e. direct derivation method based on the steady response and eigenvalue method based on complex eigenvalue analysis.

The straight driving stability of driver vehicle closed loop system is studied The effects of driver's foresee time and the stiffness of tire to critical velocity are analyzed in linear domain Using Hopf theorem,the traits of vehicle's motion are studied when the stability is lost in nonlinear domain Taking a domestic vehicle as an example,the results are validated that the vehicle will have a stable snaking motion when the straight driving stability is lost

Two methods of judging the driving stability of AFV were presented:the eigenvalue method and the method of steady response under constant input,and the expressions of stability factor and critical vehicle speed were derived.

To analyze the driving stability of the tractor-semitrailer,a coupled system composed of single point preview driver model and 3-degree-of-freedom nonlinear model was suggested to simulate it. By applying Lyapunov linear approximation theorem,the characteristic root locus of system parameters and the effects of driver preview time and cornering stiffness on the critical vehicle speed were linearly analyzed.

Analytical results show that the tire cornering stiffness significantly affects the critical vehicle speed of tractor-semitrailer,the speed goes up with the increase of cornering stiffness,showing a nonlinear relationship between them.

For instance, in a certain case, if the effects of the mechanical seal were taken into account, the systems critical speed may increase by 70-80%.

A method combining the predictor-corrector mechanism and the Netwon-Raphson method is presented to calculate the critical speed at the corresponding Hopf bifurcation point of the system.

Experimental results showed that the resonant vibration around the first critical speed was obviously suppressed by both types of passive electromagnetic damper.

The results show that the whirl speeds are always higher than the critical speed of the shaft.

In the text mentioned above a series of problems such as the forced vibrations, resonance conditions and critical speed and so forth.

This paper discusses the behavior of traffic jams with catastrophe theory. In highways, the determination of the specific condition of traffic jams-such as critical density and volumn of traffic flow, critical velocity of cars, etc(?)has been a subject in traffic engineering until now. In this paper, the critical value and the fundamantal equation of traffic jams are discussed and studied, and with an exsample the author defines that catastrophe theory is more close to the objective reality than smooth change...

This paper discusses the behavior of traffic jams with catastrophe theory. In highways, the determination of the specific condition of traffic jams-such as critical density and volumn of traffic flow, critical velocity of cars, etc(?)has been a subject in traffic engineering until now. In this paper, the critical value and the fundamantal equation of traffic jams are discussed and studied, and with an exsample the author defines that catastrophe theory is more close to the objective reality than smooth change theory (such as "The hydromechanics model" ).

The dynamic characteristics of the frame of press section on the paper machine (model 1760) were studied with the program SAP84 and SAP5, the natural frequency and dynamic response of the frame were calculated reliably. The calculation method of critical operation speed is put forward based on the theories of vibration and composition of beat frequency;the principles of determining the allowable operation speed are concluded. All of these are useful for the paper machine design.

In this pater, on the basis of automobile power train with clutch damper and dual Mass Flywheel Damper. The calculation and analysis models of system's natural performance are built,the natural frequency and natural vibration modeling of the torsion vibration systems are calculated by means of generalized Jacobi's method,and the calculations and analysis of the critical speed and critical velocity are carried out,then the influences on characteristic of the automobiled power train are obtained, this will have...

In this pater, on the basis of automobile power train with clutch damper and dual Mass Flywheel Damper. The calculation and analysis models of system's natural performance are built,the natural frequency and natural vibration modeling of the torsion vibration systems are calculated by means of generalized Jacobi's method,and the calculations and analysis of the critical speed and critical velocity are carried out,then the influences on characteristic of the automobiled power train are obtained, this will have an important meaning for the calculation and analysis of the automobile power train,the theory basis is given for the designing of the dual mass flywheel.