AN INVESTIGATION OF STRESS DISTRIBUTION IN A CATAMARAN CROSS-STRUCTURE

The objective of this thesis is to provide information regarding the distribution of transverse bending and shear stresses in a main transverse bulkhead of a catamaran cross-structure. Additionally, data is to be obtained on the width of deck plating between main bulkheads that resists transverse bending. The particular cross-structure configuration to be investigated is patterned after the United States Navy ASR-21 Class catamaran. The study is of a two-dimensional nature to eliminate the influence of the adjacent transverse bulkheads on the stress distribution. The photoelastic method of stress analysis employing a standard circular crossed polariscope in conjunction with a finite element computer program were used to conduct the investigation. The two-dimensional models were machined from Photolastic's PSM-1 material. A total of twelve models were constructed using three values of B/D. Within each B/D series, the values of A sub f/A sub w were varied. The models were simply supported and loaded in vertical and horizontal directions. A finite element grid was established for each of the models and a series of computer calculations were made using the same loading and parameter variations as for the photoelastic models. The stress distribution obtained with both methods of investigation indicates that the variation in transverse bending stress through the depth of the cross-structure is approximately linear for the vertical and horizontal loads acting separately. The stress throughout the model resulting from the combined vertical and horizontal loads is not considered typical of that likely to be encountered in a prototype ship due to the proportionally excessive horizontal load required for photoelastic testing. Three-dimensional studies should be undertaken with particular emphasis placed on the determination of the "effective breadth" of deck plating, and verification of the linearity of the transverse bending stress distribution through the depth of the cross-structure.

• Corporate Authors:

  Massachusetts Institute of Technology

  Department of Naval Architecture and Marine Engineering
  Cambridge, MA  United States  02139
• Authors:
  • Maclin, C S
• Publication Date: 1971-6

Subject/Index Terms

• TRT Terms: Catamarans; Finite element method; Photoelasticity; Structural analysis; Transverse strength; Yield stress
• Subject Areas: Marine Transportation; Materials;

Filing Info

• Accession Number: 00044170
• Record Type: Publication
• Source Agency: Massachusetts Institute of Technology
• Files: TRIS
• Created Date: May 11 1973 12:00AM