The paper follows from the theory of explosion and interaction of an impact wave formed by the explosion and a structure..As a rule, a number of simplifying assumptions must be applied as regards the characteristics of the explosion and of the threatened structure to analyze the structure. As example of dynamic analysis of a new reinforced concrete structure, loaded with a blast wave was used to apply the principles of simpflified ingineering analysis of an explosion-loaded structure. The way of structure failure was analyzed based on time courses of calculated internal forces and displacenets of individual structure elements. The criteria of structural elements failure due to explosion load effects were determined as a part of the dynamic structure response assessment. and Obsahuje seznam literatury
The paper investigates ways to model the response of vibro-isolation mounts that utilise viscoelastic materials. Simple models based on linear and nonlinear static stiffness are developed. Dynamic response is approximated through appropriate scaling of the viscoelastic Young's modululs and use of the measured material loss factor. The approach is validated using cylindrical mounts made of polyurethane. The response of a 68 kg mass supported by two mounts and subjected to two different high-amplitude shock loads is predicted. Measured and predicted behaviour correlate closely for the nonlinear model while the linear model gives a reasonable representation. It is noted that the sensitivity of such mounts to temperature is high: the change in response associated with a temperature excursion of 10 °C is significantly greater than the inaccuracy involved with using the linear model. and Obsahuje seznam literatury
Experimental measurement is performed on a simple fibre-mass system: a moving mass coupled with the frame by a fibre. Dynamic response of the mass is measured. The same system is numerically investigated by means of a simple multibody model. The influence of the model parameters on the coincidence of results of experimental measurements and of simulations are evaluated. The simulations aim is to create a phenomenological model of a fibre, which will be utilizable in fibre modelling in the case of more complicated mechanical or mechatronic systems. and Obsahuje seznam literatury
The article provides a method of mathematical modelling of the dynamic properties of the electric locomotive wheelset drive. The linkage of the traction motor by means of the rotor pinion gear with the gear of wheelset drive is considered. The impact of couplings and operation conditions on the dynamic properties is studied. The method of decompositon into subsystems is applied for derivation of mathematical model of an interconnected system. This model is used for the calculation of modal values and also for investigating the forced vibration excited by pulsation moments of the asynchronous traction motor. The method is applied to a particular drive of the locomotive SKODA 109E. and Obsahuje seznam literatury
Submitted paper deals with preparation of the X-DIA aeroelastic demonstrator component wind tunnel tests. The paper is focused on design, analysis and manufacturing of new composite foreplanes, FE analyses of the X-DIA Component Model (static
aeroelasticity, flutter, dynamic responses) and optimization study of the demonstrator wind tunnel support device. Analyses were performed by means of the MSC.NASTRAN program system. and Obsahuje seznam literatury