International Shipbuilding Progress - Volume 19, issue 218

Authors: Jones, Norman

Article Type: Research Article

Abstract: A review is made of the literature which has been published on the theoretical and experimental plastic behavior of laterally loaded beams and rectangular plates. This article focuses attention on these particular structures since they are used extensively in marine vehicles and structural designs in general. It is well known that investigations into the static and dynamic inelastic behavior of structures are simplified considerably when elastic effects can be disregarded. It is shown herein that quite reasonable agreement can be achieved between experimental results and the corresponding rigid-plastic predictions provided that both the influence of finite lateral deflections, or geometry …changes, and the effect of material strain-rate sensitivity are retained when appropriate. The results of some recent studies are also reported which indicate that extremely small in-plane displacements at the supports of beams and plates can influence significantly the structural response. Show more

DOI: 10.3233/ISP-1972-1921801

Citation: International Shipbuilding Progress, vol. 19, no. 218, pp. 313-327, 1972

Authors: Wereldsma, R.

Article Type: Research Article

Abstract: From two-dimensional considerations a relation has been derived between the dynamic propeller shaft forces and the speed of ship and propeller. A factor, defined as the ‘index of unsteadiness’, enables the prediction of propeller vibratory forces, for conditions different from a test condition. Considerations have been made concerning the level of the vibratory output of multiple propeller arrangements, as compared to regular single propeller arrangements.

DOI: 10.3233/ISP-1972-1921802

Citation: International Shipbuilding Progress, vol. 19, no. 218, pp. 328-332, 1972

Authors: van der Meulen, J.H.J.

Article Type: Research Article

Abstract: In a high speed water tunnel, incipient and desinent cavitation are investigated on a series of hemispherical nosed teflon bodies. The results are compared with those measured previously on a series of stainless steel bodies. The experiments cover a wide range of flow velocities and air contents of water. Large differences, both in cavitation appearance and in desinence and inception values are found between the teflon and stainless steel bodies. While desinent cavitation on the stainless steel bodies was probably caused by stream nuclei, it is shown that cavitation on the teflon bodies is produced by surface nuclei.

DOI: 10.3233/ISP-1972-1921803

Citation: International Shipbuilding Progress, vol. 19, no. 218, pp. 333-341, 1972

Authors: Prank, C.

Article Type: Research Article

Abstract: A brief mathematical description is given of the propulsion system, consisting of a power source and a controllable pitch propeller. The selection of control parameters is discussed for both diesel engines and gas turbine installations. After selection and design of the control system, the behaviour of the entire plant during manoeuvres can be simulated by means of a mathematical model programmed for a computer. This is illustrated by some typical examples.

DOI: 10.3233/ISP-1972-1921804

Citation: International Shipbuilding Progress, vol. 19, no. 218, pp. 342-348, 1972