A flat steel ribbon wound pressure vessel was adopted by ASME Code Case 2229 on 16 August 1996. By considering the additional strength caused by friction between ribbon layers, the authors deduced equations for prediction of longitudinal and hoop bursting pressure of such vessels. The calculation results from the equations, which are easy to calculate and convenient to apply in the engineering, are in excellent agreement with experimental results. It is the theoretical base for equal strength design in axial and circumferential direction. In addition, the criterion of failure form of such a vessel is also given.

Flat steel ribbon wound pressure vessels have been adopted by the ASME boiler and Pressure Vessel Code, Section Ⅷ, Division J and Divesion 2. An excellent safety and scrive record has been built up in the past 34 years. Based on the interfacial friction model proposed by Zheng [1], a more accurate method for predicting the stresses in a flat steel ribbon wound ressure vessel is offered in this paper, taking account of the axial displacement, the change in the helical winding angle, the interfacial friction between ribbon layers and the effect of lamination. Comparison between experimental results of five test vessels with and inside diameter varying from 350 to 1000mm, four different helical winding angles (18, 24, 27 and 30°), two width-thickness rations of the ribbon (20 and 22.86) and rosults of oalculation using the stress formulae available demonstrates that the method in this paper is more accurate and that interfacial friction gives a marked strengthening contribution to the axial strength of the vessel.

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.

Considering the fact that the required thickness of a hemispherical head for pressure loading is only half of that necessary for a cylindrical shell, the authors have developed a proprietary junction of shell to hemispherical head where the head is thinner than the shell. In the past 5 years, more than 100 high-pressure vessels with such junctions have been manufactured and safely used in the People's Republic of China. Theoretical investigations as well as engineering applications show that such junctions are rational in structure, convenient in fabrication and low in cost. For example, for a vesscl with an inner diameter of 1000 mm and design pressurc of 31.4MPa, using thc new junction, the head weight is reduced by 54.3 and 27.4 per cent respectively in comparison with a forged fiat head and a hemispherical head with equal thickness of shell. The larger the vessel, the grcater the economic benefits it achieves, In this paper, the authors describe its basic structure, stress characteristics and the engineering design method for the unique junction.

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.