Grillage Analysis of Waffle Slab Structures at Edge Column Panel

Author(s):  
A.F. Hussein
Author(s):  
Nithyambigai G. ◽  
Rameshwaran P.M. ◽  
Stella Mary F.
Keyword(s):  

1982 ◽  
Vol 19 (01) ◽  
pp. 52-72
Author(s):  
William A. Henrickson ◽  
John S. Spencer

The need exists for a simplified structural review guide to enable U.S. Coast Guard marine inspectors to verify the structural adequacy of aluminum crewboats. The authors have developed such a guide. Typical existing crewboat forms and service speeds have been used to reduce the determination of impact pressures to a function of length and displacement. A design stress limit for the cyclic loading of the bottom structure has been determined based on wave observation data. Plating design has been verified by a comparison of sizing by beam theory versus elastoplastic analysis. A simplified grillage analysis has been used to determine the level of support provided by longitudinal plate girders or keelsons. A worked example and tables of section moduli for typical extrusions attached to plating are included as appendices.


Author(s):  
Sungchan Kim ◽  
Cheolho Ryu ◽  
Youngho Kim ◽  
Changbong Han ◽  
Dong Geun Kim

There are many PE(Pre-Erection) Blocks in open areas of the shipyard, which are supported by the wooden, concrete, or steel supports. Their position and numbers are decided on a basis of the workers’ experiences. Recently, many shipyards have been making PE blocks with various shape and weight distribution because of the variety of kinds of ships and their building technology. Seriously, they are treating blocks which have not been experienced. In order to evaluate the reliability of all support plans of PE Blocks in such situation, many man hours (MH) are consumed, and the special knowledge and technology about structural analysis are required. We proposed how to conveniently and quickly evaluate the structural safety on PE block supports and developed an application system to implement the evaluation process with three dimensional part models of the PE block and their weight information. The evaluation is based on the simplification to a grillage model of a PE block and its grillage analysis. The load distribution on the grillage model is calculated by two approaches. The first is that the load distribution on the grillage nodes are estimated with the real weight and the center of gravity of each part of a PE block, which can be provided from design databases of the shipyard. The other is that the load distribution is optimally estimated only with the weight and the center of gravity of sub blocks of a PE block. The latter is useful in the case that block information of mother ships can be obtained without the detail design of the PE block. The integrated system has been comprehensively implemented in order to make the grillage model from the three dimensional CAD models of the PE block and their weight information, and to perform the grillage analysis for the reaction forces on the block supports. In the application program, the grillage model can be automatically built from CAD models of PE block. Also the grillage can be modified by inserting, splitting, and deleting a beam element.


1988 ◽  
Vol 15 (5) ◽  
pp. 821-827
Author(s):  
Leslie G. Jaeger ◽  
Baidar Bakht

It is now well established, strictly speaking, that a grillage composed solely of orthogonal beams can be used for the analysis of slab bridges only when the Poisson's ratio (v) of the slab material is taken to be zero. The effect on the various responses of using a grillage composed solely of orthogonal beams, and ignoring v, is discussed in this paper, and a method is given to account for the effect on transverse moments of making this simplifying assumption. The paper also contains procedures to determine the peak values of the various responses, as well as their integrated values over a given width of the bridge. Using these procedures, it is shown that the spacings of grillage beams in the conceptual grillages used for analysis do not influence the results as much as is generally believed. Key word: grillage analogy, longitudinal moment, Poisson's ratio, slab bridges, transverse moments.


1989 ◽  
Vol 5 (1) ◽  
pp. 41-50 ◽  
Author(s):  
E. Sordo ◽  
A. Terán ◽  
J. J. Guerrero ◽  
H. Juárez ◽  
J. Iglesias

This paper describes the study of a twelve floor concrete building with a waffle slab system located 300 meters from the accelerometer at Secretaria de Comunicaciones y Transportes (S.C.T) in Mexico City. First, the reduced seismic coefficient associated with the failure of the critical story is calculated by a linear dynamic analysis which reproduces the damage provoked by the 1985 earthquake to the real structure. Second, the ductility factor associated with the damaged stories is obtained through a step-by-step non-linear dynamic analysis. Finally, the peak value of the S.C.T. maximum ordinate for spectral response corresponding to 5 percent of critical damping was determined from this analysis.


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