Recent Research on Dynamic Behavior of Large Great Lakes Bulk Carriers

1984 ◽  
Vol 21 (04) ◽  
pp. 339-355
Author(s):  
Stanley G. Stiansen

This paper reviews several research projects undertaken by the American Bureau of Shipping in the recent past which are of particular interest to Great Lakes vessels. These projects cover five areas of research, namely, linear springing prediction, analytical and experimental investigation of nonlinearity in springing, pressure correlation, ship vibrations, and fatigue behavior.

1909 ◽  
Vol 29 ◽  
pp. 619-647 ◽  
Author(s):  
E. M. Wedderburn ◽  
W. Watson

One of the authors having made an experimental investigation on the currents produced in a trough of water by a blast of air driven along the surface of the water, it was desired to test the correctness of his deductions by actual observations in a large lake. Loch Ness was chosen on account of its length and uniformity of basin, as it was thought that the length and narrowness of the loch would lead to clearly defined currents being set up in the lake. The sequel showed, as in the case of observations on seiches, that it would have been better to confine attention to a smaller lake, for a twofold reason, (1) because in a large lake the difficulties of observations are much greater than in a small lake during stormy weather, and in very deep lakes the difficulties in the way of obtaining a fixed point from which to use the current meter are formidable, and (2) because it would seem from a few observations made in Loch Garry (Ness Basin) that currents are more defined and more regular in small than in great lakes.


Author(s):  
Kay Langschwager ◽  
Alexander Bosch ◽  
Eliane Lang ◽  
Jürgen Rudolph ◽  
Michael Vormwald ◽  
...  

Austenitic stainless steel of type X6CrNiNb18-10 (1.4550) is a widely used material in piping and components of nuclear power plants. The fatigue behavior of these components is often operationally determined by thermomechanical strains and corresponding stresses. Welded structures lead to complex stresses in the component and potential fatigue lifetime reductions. Various geometrical and microstructural inhomogeneities in welded structures represent the main factors of influence. Nevertheless, clear identification and quantification of various factors of influence are issues still to be resolved. Within the framework of an ongoing research project, the experimental investigation comprises uniaxial and biaxial fatigue experiments on welded joints which cover temperatures from 25°C to 350°C. Furthermore, a key issue deals with the thermomechanical fatigue behavior of machined and unmachined butt weld seams. A special focus is set on typical low cycle fatigue (LCF) tests in order to explain the behavior of the base material and the weld material to identify the influence of microstructural inhomogeneities. In addition, specimens manufactured directly from the pipe components are tested to examine the influence of the butt weld seam geometry. For a better understanding of the local strain effects, optical strain field measurements (OSFM) are conducted and used to validate numerical simulation. The finite element method (FEM) is utilized to expand the parameter space and identify the main parameters. Experimental and numerical results show that fatigue failure occurs either in the base metal in the vicinity of the welded zone or in the top layer of the weld, depending on the loading conditions. This knowledge is used to develop an approach to fatigue lifetime estimation.


2000 ◽  
Vol 43 (2) ◽  
pp. 283-292 ◽  
Author(s):  
Shuji NISHIYAMA ◽  
Norio UESUGI ◽  
Toru TAKESHIMA ◽  
Yuji KANO

1995 ◽  
Vol 32 (03) ◽  
pp. 179-185
Author(s):  
Eric Reeves ◽  
Laurie Perry

In 1989 the U.S. Coast Guard promulgated regulations implementing Annex V to Marpol 73/78, which regulates the discharge of "garbage" from ships. Since that time it has become apparent that Marpol V, an international regime designed for the high seas, does not translate into a workable regime for the Great Lakes without some modification for the special problem of cargo residue discharges from dry bulk carriers. Application of Marpol V to the Great Lakes by the United States has also created an anomaly, because Canada has yet to do so, in large part because of serious concerns about its application to cargo residues on the Great Lakes. On September 22, 1993 the U.S. Coast Guard Ninth District put out an interim enforcement policy designed to provide a reasonable balance between the need to protect the environment of the lakes against any possible harm while taking account of the need for safe operation of commercial dry bulk carriers. At the same time, in cooperation with the Canadian Coast Guard Central Region and the U.S. National Oceanic and Atmospheric Administration, the U.S. Coast Guard Ninth District is developing better scientific information about the possible effects of cargo residues in order to build a scientific basis for a revised regulatory regime. As the scientific study progresses, the Ninth Coast Guard District continues to make modifications to the current enforcement policy, in consultation with Canadian Coast Guard Central Region, the scientific community, industry, and environmental groups. The final goal is a reasonably balanced and consistent regime on both sides of the lakes, in accordance with the mandates of the Great Lakes Water Quality Agreement.


1984 ◽  
Vol 28 (02) ◽  
pp. 141-150
Author(s):  
Armin W. Troesch

The results of an experimental and theoretical study investigating the main hull girder vibrations of Great Lakes bulk carriers are presented. The source of the excitation is considered to be the incident waves. The emphasis of the work is to understand the hydrodynamic aspects of ship springing. Theoretical calculations based upon a short-wavelength assumption compare well with experiments.


1978 ◽  
Vol 15 (03) ◽  
pp. 287-296
Author(s):  
John B. Woodward

The rise of fuel prices above their traditional levels suggests that the thermal energy in diesel exhaust gas ("waste heat") should be used by the Great Lakes ships in a manner similar to established ocean practice. This paper discusses the important generalities in this use, the magnitude of the energy source from several Great Lakes propulsion engines, and then outlines two schemes for its application by a self-unloading ore carrier of contemporary design. Brief economic analyses show that one scheme is attractive enough to justify more detailed consideration of its use in future ships.


1966 ◽  
Vol 3 (02) ◽  
pp. 200-211
Author(s):  
Alex Vedeler

Although little statistical information is available regarding the actual wave conditions on the Great Lakes, considerable reductions are possible in the required scantlings of the present and future Great Lakes bulk carriers. Utilizing the available knowledge about the strength of ocean-going vessels and modifying this for the Lakes, rational formulas are developed for the required midship section modulus and moment of inertia. The present Lake strength norm for the large carriers is a linear extrapolation of requirements developed almost 50 years ago and has led to a required midship section modulus considerably in access of what is necessary. The formulas developed in this paper indicate that a saving of around 15 percent in the steel weight is possible within the present state of the art. As more detailed information of the wave spectrum becomes available in the future, further savings should be possible.


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