Sensitivity Study About Ultimate Strength and Postbuckling Behavior of Stiffened Box Deck Girder Under Compression

2021 ◽  
Author(s):  
Chunqi Zhou ◽  
Dan Song
Author(s):  
Chunqi Zhou ◽  
Dan Song

Abstract The proper determination of this paper is to study the ultimate strength and postbuckling behavior for complicated stiffened deck girders of offshore platforms. Normally, offshore platforms are designed with reinforcing stiffeners on box deck girder. The box deck of column stabilized platform will be simulated with FEM software ABAQUS. Linear eigenvalue analysis is firstly applied to introduce the initial imperfection into the structure. Then the non-linear postbuckling analysis for the box deck girder will illustrate ultimate strength and the failure mode under axial load after collapse. The ways how the stiffeners, eigenmode and imperfections influence the ultimate capacity will also be analyzed. Comparing variable elements affecting the structural strength, the work shows the offshore box deck girder section from the engineering project in this paper is quite robust to the axial compression. For this kind of robust design, such as the box deck girder, the eigenmode selection and amplitude of imperfection will exert slight effects on the ultimate strength, but the severe imperfections will accelerate the local buckling. Stiffeners design will exert dramatic influence on the ultimate strength and postbuckling behaviors. And the work to find the optimum balance among structural strength variable load and allowable imperfections seems to be very promising in engineering. The conclusions provide a more clear insight into the further optimization of the offshore square structure design.


1964 ◽  
Vol 7 (4) ◽  
pp. 389-393 ◽  
Author(s):  
David C. Shepherd ◽  
Robert Goldstein ◽  
Benjamin Rosenblüt

Two separate studies investigated race and sex differences in normal auditory sensitivity. Study I measured thresholds at 500, 1000, and 2000 cps of 23 white men, 26 white women, 21 negro men, and 24 negro women using the method of limits. In Study II thresholds of 10 white men, 10 white women, 10 negro men, and 10 negro women were measured at 1000 cps using four different stimulus conditions and the method of adjustment by means of Bekesy audiometry. Results indicated that the white men and women in Study I heard significantly better than their negro counterparts at 1000 and 2000 cps. There were no significant differences between the average thresholds measured at 1000 cps of the white and negro men in Study II. White women produced better auditory thresholds with three stimulus conditions and significantly more sensitive thresholds with the slow pulsed stimulus than did the negro women in Study II.


2017 ◽  
Vol 04 (03) ◽  
pp. 231-236 ◽  
Author(s):  
Barham S. Mahmood ◽  
Jagar Ali ◽  
Shirzad B. Nazhat ◽  
David Devlin

AIAA Journal ◽  
2001 ◽  
Vol 39 ◽  
pp. 308-314
Author(s):  
G. Greschik ◽  
M. Mikulas ◽  
A. Palisoc ◽  
C. Cassapakis ◽  
G. Veal
Keyword(s):  

2021 ◽  
Author(s):  
Hiroaki Ishikawa ◽  
Atsushi Ueno ◽  
Shinya Koganezawa ◽  
Yoshikazu Makino ◽  
Bernd Liebhardt ◽  
...  

1977 ◽  
Vol 1977 (141) ◽  
pp. 190-197 ◽  
Author(s):  
Yuzuru Fujita ◽  
Toshiharu Nomoto ◽  
Osamu Niho

2020 ◽  
Vol 86 (5) ◽  
pp. 43-51
Author(s):  
V. M. Matyunin ◽  
A. Yu. Marchenkov ◽  
N. Abusaif ◽  
P. V. Volkov ◽  
D. A. Zhgut

The history of appearance and the current state of instrumented indentation are briefly described. It is noted that the materials instrumented indentation methods using a pyramid and ball indenters are actively developing and are currently regulated by several Russian and international standards. These standards provide formulas for calculating the Young’s modulus and hardness at maximum indentation load. Instrumented indentation diagrams «load F – displacement α» of a ball indenter for metallic materials were investigated. The special points on the instrumented indentation diagrams «F – α» loading curves in the area of elastic into elastoplastic deformation transition, and in the area of stable elastoplastic deformation are revealed. A loading curve area with the load above which the dF/dα begins to decrease is analyzed. A technique is proposed for converting «F – α» diagrams to «unrestored Brinell hardness HBt – relative unrestored indent depth t/R» diagrams. The elastic and elastoplastic areas of «HBt – t/R» diagrams are described by equations obtained analytically and experimentally. The materials strain hardening parameters during ball indentation in the area of elastoplastic and plastic deformation are proposed. The similarity of «HBt – t/R» indentation diagram with the «stress σ – strain δ» tensile diagrams containing common zones and points is shown. Methods have been developed for determining hardness at the elastic limit, hardness at the yield strength, and hardness at the ultimate strength by instrumented indentation with the equations for their calculation. Experiments on structural materials with different mechanical properties were carried out by instrumented indentation. The values of hardness at the elastic limit, hardness at the yield strength and hardness at the ultimate strength are determined. It is concluded that the correlations between the elastic limit and hardness at the elastic limit, yield strength and hardness at the yield strength, ultimate tensile strength and hardness at the ultimate strength is more justified, since the listed mechanical characteristics are determined by the common special points of indentation diagrams and tensile tests diagrams.


Sign in / Sign up

Export Citation Format

Share Document