In this paper, the hydro-expanding principle for a double-layered tube is set out in detail. The force state of a double-layered tube was analyzed during the process of hydro-forming. The stress and strain for the inner and outer tubes were evaluated using theories of elasticity and plasticity. By using the relation of deformed compatibility of hoop strain, suitable conditions of hydraulic expansion and variable range of hydro-expanding pressure are given, and formulae of hydro-expanding pressure related to residual contact pressure are derived. The results are applicable to cases where the inner tube is both thin-walled and thick-walled.

energy deposition into targets and beam absorbers in high-energy accelerator leads to temperature rise at an enormous rate, giving rise to thermally induced stress waves. Understanding and predicting resulting stresses are crucial for robust design and safe operation of such devices. In this paper, a closed form expressions for the induced stresses in cylindrical rods subjected to rapid partial energy deposition have been directly derived; it is then used to estimate highest stress of long cylindrical absorbers and to test the accuracy of thermal shock simulation with Finite Element Analysis (FEA) codes. Characteristics of such stresses were discussed in detail. It was found that ANSYS may produce accurate details in thermal shock simulation if element size and time step used in simulation model meet the criteria proposed by Zheng etc. in another paper.

The stochastic resonance phenomenon is investigated in the presence of colored noise. The solutions of the signalto-noise ratio gain and the characteristic time are put forward. By means of tuning system parameters, the ability of a bistable system driven by colored noise to process a weak multi-frequency signal can be enhanced. It is found that the effects of the noise-correlation time on signal processing are not great. Furthermore, this method can be applied to sampling signal processing.

The paper presents a numerical method of realizing stochastic resonance (SR) by tuning system parameters. Firstly, a simple and effective method of evaluating the system response speed λ1 is introduced. Then the parameterinduced SR problem can be reduced to the parameter optimization problem under the condition λ1=const. To solve this optimization problem, we put forward the following techniques: (i) compensate the deviation from the prescribed system response speed λ1 at each step, (ii) take the curve length increment on the parameter plane as the step size in searching the maximal signal-to-noise ratio (SNR) gain. Finally, a numerical simulation confirms the effectiveness of this method.

Over the past 30 years, more than 7000 layered vessels using at-ribbon-wound cylindrical shells have been manufactured in the People's Republic of China. Theoretical as well as experimental investigations show that there are distinct economical and engineering advantages when using such vessels. The vessel provides the industry with a competitive design suitable for use in the oil refining, chemical and petrochemical fields. The present state of art in strength, design method and some related areas of development of such vessels are described.