A model technique for bending strength of tubular joints

One shape of ‘Y—T’ joint has been die-cast in a tin-lead alloy. Twenty-one models have been tested in in-plane or out-of-plane bending, loading one or both braces. The results are presented non-dimensionally as Ultimate Strength Reduction Ratios (USRR) i.e., as fractions of (simply calculated) bending moments which would have ensured failure of the brace remote from the joint. The results from the tin-lead models agreed with relevant results from steel models. Parametric equations derived mainly from ‘T’ joint data predict the failure of 90 degree braces well, but underestimate the strength of 45 degree braces in in-plane and out-of-plane bending. Plastic collapse occurs on the compressed side of the braces before tearing on the tension side.

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Stress Concentrations in DT/X Square-to-Square and Square-to-Round Tubular Joints

Journal of Offshore Mechanics and Arctic Engineering ◽

10.1115/1.2920132 ◽

1994 ◽

Vol 116 (2) ◽

pp. 49-55 ◽

Cited By ~ 2

Author(s):

A. K. Soh ◽

C. K. Soh

Keyword(s):

Stress Concentration ◽

Bending Moment ◽

Bending Moments ◽

Axial Loads ◽

Stress Concentrations ◽

Tubular Joints ◽

Out Of Plane ◽

Concentration Factors ◽

Plane Bending ◽

Stress Concentration Factors

A parametric stress analysis of DT/X square-to-square and square-to-round tubular joints subjected to axial loads, in-plane, and out-of-plane bending moments has been performed using the finite element technique in order to provide a sound basis for using such sections in the design of complex structures. The results of this analysis are presented as a set of equations expressing the stress concentration factor as a function of the relevant geometric parameters for various loading conditions. A comparison is made between the results obtained for square-to-square and square-to-round tubular joints and those obtained for round-to-round tubular joints by other researchers. In general, the stress concentration factors for square-to-square tubular joints are the highest, followed by those of the corresponding round-to-round joints, with those of the corresponding square-to-round joints the lowest when the joints are subject to axial loads. In the case of in-plane bending moment, the stress concentration factors for square-to-square joints are generally still the highest, but followed by those of the corresponding square-to-round joints, with those of the corresponding round-to-round joints the lowest. However, the stress concentration factors for the three types of joint are comparable when they are subject to out-of-plane bending moments.

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Low Cycle Fatigue of T-Tubular Joints With Out-of-Plane Bending Loading

Volume 4: Materials Technology; Ocean Engineering ◽

10.1115/omae2007-29351 ◽

2007 ◽

Cited By ~ 4

Author(s):

Fro̸ydis Boge ◽

Torgeir K. Helland ◽

Stig Berge

Keyword(s):

Low Cycle Fatigue ◽

Hot Spot ◽

Fatigue Loading ◽

Published Data ◽

Hot Spot Stress ◽

Tubular Joints ◽

R Ratio ◽

Out Of Plane ◽

Plane Bending ◽

Bending Loading

Tubular T-joints were fatigue tested with out-of-plane bending loading. Six models were tested, three models with R-ratio of 0 and three with R = −1. Hot spot stress was measured for the brace and for the chord using the ECSC linear extrapolation procedure. Fatigue loading was applied in load control, to obtain through thickness cracking at a number of cycles in the range 4 000–200 000 cycles. The data were analysed and compared with published data and with current fatigue design criteria for tubular joints.

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Stress Concentrations in T/Y and K Square-to-Square and Square-to-Round Tubular Joints

Journal of Offshore Mechanics and Arctic Engineering ◽

10.1115/1.2919974 ◽

1992 ◽

Vol 114 (3) ◽

pp. 220-230 ◽

Cited By ~ 7

Author(s):

A. K. Soh ◽

C. K. Soh

Keyword(s):

Stress Concentration ◽

Bending Moments ◽

Axial Loads ◽

Stress Concentrations ◽

Tubular Joints ◽

Out Of Plane ◽

Concentration Factors ◽

Plane Bending ◽

Stress Concentration Factors ◽

Element Technique

A parametric stress analysis of T/Y and K square-to-square and square-to-round tubular joints subjected to axial loads, in-plane and out-of-plane bending moments has been performed using the finite element technique in order to provide a sound basis for using such sections in the design of complex structures. The results of this analysis are presented as a set of 42 equations expressing the stress concentration factor as a function of the relevant geometric parameters for various loading conditions. A comparison is made between the results obtained for square-to-square and square-to-round tubular joints and those obtained for round-to-round tubular joints by other researchers. In general, the stress concentration factors obtained from round-to-round and square-to-round tubular joints are closer as compared with those of the corresponding square-to-square tubular joints. Moreover, the stress concentration factors for square-to-square tubular joints are generally lower than those of the corresponding round-to-round and square-to-round tubular joints when the joints are subject to axial loads; but the reverse is true when the joints are subject to in-plane bending moments. However, the stress concentration factors for the three types of joint are comparable when they are subject to out-of-plane bending moments.

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Stresses in Curved, Circular Thin-Wall Tubes

Journal of Applied Mechanics ◽

10.1115/1.3630058 ◽

1963 ◽

Vol 30 (1) ◽

pp. 134-135

Author(s):

E. A. Utecht

Keyword(s):

Thin Wall ◽

Bending Moments ◽

Circular Tubes ◽

Out Of Plane ◽

Thin Walled ◽

Plane Bending

Curves are presented which give stress intensification factors for curved, thin-walled circular tubes under various combinations of in-plane and out-of-plane bending moments.

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