Experimental Study on the Application of Holography to Thermal Stress Evaluation of Luninarire Components

The temperature distribution of the bridge and its thermal effect has always been an important issue for researchers. To investigate the temperature distribution and thermal stress in the steel-concrete composite bridge deck, a 1:4 ratio temperature gradient effect experimental study was carried out in this paper. First, a set of experimental equipment for laboratory temperature gradient loading was designed based on the principle of temperature gradient caused by solar radiation, the temperature gradient obtained from the measurements were compared with the specifications and verified by the FE method. Next, the loading of the steel-concrete composite deck at different temperatures was performed. The thermal stress response and change trend of the simply supported and continuously constrained boundary conditions under different temperature loads were analyzed. The experimental results show that the vertical temperature of steel-concrete composite bridge deck is nonlinear, which is consistent with the temperature gradient trend of specifications. The vertical temperature gradient has a great influence on the steel-concrete composite bridge deck under different constraints, and the extreme stress of concrete slab and steel beam is almost linear with the temperature gradient. Finally, some suggestions for steel-concrete composite deck design were provided based on the research results.

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2801 Thermal stress evaluation for branch with closed end

The proceedings of the JSME annual meeting ◽

10.1299/jsmemecjo.2007.1.0_677 ◽

2007 ◽

Vol 2007.1 (0) ◽

pp. 677-678

Author(s):

Toru OUMAYA ◽

Akira NAKAMURA ◽

Nobuyuki TAKENAKA

Keyword(s):

Thermal Stress ◽

Stress Evaluation

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Evaluation of Thermal Stress Ratchet in Plastic FEA

Pressure Vessel and Piping Codes and Standards ◽

10.1115/pvp2002-1215 ◽

2002 ◽

Cited By ~ 5

Author(s):

Yukinori Yamamoto ◽

Norimichi Yamashita ◽

Masaaki Tanaka

Keyword(s):

Finite Element ◽

Thermal Stress ◽

Stress State ◽

Plastic Strain ◽

Axial Stress ◽

Equivalent Plastic Strain ◽

Hardening Material ◽

Linear Temperature ◽

Stress Evaluation ◽

Elastic Core

Alternative stress evaluation criteria suitable for Finite Element Analysis (FEA) proposed by Okamoto et al. [1] have been studied by the Committee on Three Dimensional Finite Element Stress Evaluation (C-TDF) in Japan. Thermal stress ratchet criteria in plastic FEA are now under consideration. Two criteria are proposed: evaluating variations in plastic strain increments and evaluating variations in the width of elastic core. To verify the validity of these criteria, calculations were performed for several typical models in C-TDF [2]. This paper shows the results of a simple cylinder model. Cyclic plastic analyses were performed applying sustained internal pressure and alternating linear temperature distribution through the wall. Analyses were performed with various load ranges to evaluate the precise ratchet limit and its behavior across the limit. Both pressure and thermal stress were given parameters. In the analyses, Elastic-Perfectly-Plastic (EPP) material was used and also strain hardening material for comparison. The ratchet limit in the Code [3] is based on Miller’s theoretical analysis [4] for a cylinder assuming a uni-axial stress state, whereas real vessels are in multi-axial stress state. By our calculations, we also examined the ratchet limit in real vessels. The results show that for the cylinder in a multi-axial stress state, the ratchet limit rises 1.2 times the ratchet limit by the Code. The evaluation results show that variations in equivalent plastic strain increments can be used for ratchet criterion and ratcheting can be assessed by confirming the presence of elastic core in the second cycle.

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