Dynamic Response Analysis of Butt Joint of HTS-A Steel Considering Welding Residual Stresses

2013 ◽  
Vol 423-426 ◽  
pp. 944-950
Author(s):  
Wei Shen ◽  
Ren Jun Yan ◽  
Lin Xu ◽  
Kai Qin ◽  
Xin Yu Zhang ◽  
...  

This paper uses both numerical simulation method and experimental research method to study on welding residual stress of high-strength steel of the cone-cylinder hull. Welding is often accompanied by a larger welding residual stress, which directly affects the safety and service life of the hull structure. In order to obtain the distribution of the welding residual stress, the welding procedure was developed by its parameter language by using FE analysis software in this paper. Then the welding residual stress of hot spot region was measured through X-ray nondestructive testing method, and compared it with simulation results. Finally, considering the residual stress as the initial stress, this paper analyzed dynamic response process of the welding structure under combined actions of the welding residual stress and multiaxial loads, which could more accurately determine the stress of welding structure and the location of fatigue risk point. According to the amplitude of damage parameters and strain time-history curve, we can estimate the fatigue life of structure by selecting the corresponding damage models.

Author(s):  
Dean Deng ◽  
Kazuo Ogawa ◽  
Nobuyoshi Yanagida ◽  
Koichi Saito

Recent discoveries of stress corrosion cracking (SCC) at nickel-based metals in pressurized water reactors (PWRs) and boiling water reactors (BWRs) have raised concerns about safety and integrity of plant components. It has been recognized that welding residual stress is an important factor causing the issue of SCC in a weldment. In this study, both numerical simulation technology and experimental method were employed to investigate the characteristics of welding residual stress distribution in several typical welded joints, which are used in nuclear power plants. These joints include a thick plate butt-welded Alloy 600 joint, a dissimilar metal J-groove set-in joint and a dissimilar metal girth-butt joint. First of all, numerical simulation technology was used to predict welding residual stresses in these three joints, and the influence of heat source model on welding residual stress was examined. Meanwhile, the influence of other thermal processes such as cladding, buttering and heat treatment on the final residual stresses in the dissimilar metal girth-butt joint was also clarified. Secondly, we also measured the residual stresses in three corresponding mock-ups. Finally, the comparisons of the simulation results and the measured data have shed light on how to effectively simulate welding residual stress in these typical joints.


2015 ◽  
Vol 88 ◽  
pp. 1296-1309 ◽  
Author(s):  
Ninshu Ma ◽  
Zhipeng Cai ◽  
Hui Huang ◽  
Dean Deng ◽  
Hidekazu Murakawa ◽  
...  

2014 ◽  
Vol 996 ◽  
pp. 457-462 ◽  
Author(s):  
Thomas Schaupp ◽  
Dirk Schröpfer ◽  
Arne Kromm ◽  
Thomas Kannengiesser

Beside quenched and tempered (QT) high strength steels advanced technologies in steel manufacturing provide steels produced by the thermo-mechanical controlled process (TMCP) with yield strength of 960 MPa. These steels differ in the carbon and micro-alloying element content. With variation of heat control TIG-welded dummy seams on both steel types were performed. Analyses concerning microstructure and residual stress evolution due to welding showed typical stress distributions according to common concepts. Yet, the TMCP-steel shows higher residual stresses than the QT-steel.


2011 ◽  
Vol 255-260 ◽  
pp. 1159-1162 ◽  
Author(s):  
Xin Li Bai ◽  
Yuan Yuan Fan ◽  
Wei Yu ◽  
Dan Fei Wang

Dynamic response analysis is carried out for an aqueduct structure of the South-to-North Water Transfer Project. The interaction of water and aqueduct wall is simplified using Housner method. Six different water depths (empty aqueduct, 1/4 water depth, 1/2 water depth, 3/4 water depth, designed water depth and full water depth) are considered and calculation is conducted using time-history analysis method. The variation rule of dynamic stress and dynamic displacement are gained under different water depths. Results show that water has great influence on aqueduct body and its dynamic response. Dynamic displacement and dynamic stress of the aqueduct structure increase with the aqueduct water level increases. When water depth is bigger, dynamic displacement response and dynamic stress response are later than corresponding earthquake excitation. The relative stiffness of the longitudinal beam and the transverse beam should be fully considered in order to reduce stress concentration of aqueduct body.


2014 ◽  
Vol 912-914 ◽  
pp. 1534-1537
Author(s):  
Shao Bo Zhang ◽  
Ke Lun Wei ◽  
Bi Jian Xiao

This paper adopts large finite element software ANSYS to establish finite element model of twin-tower building with enlarged base, uses dynamic time history analysis method for seismic response calculation, compare and analyze the calculation results of twin-tower building with enlarged base under elastic boundary conditions and rigid boundary conditions. The results showe that dynamic response for model under elastic boundary conditions is larger than dynamic response for model under rigid boundary conditions, and elastic boundary conditions is more close to the actual situation.


2011 ◽  
Vol 25 (31) ◽  
pp. 4285-4288 ◽  
Author(s):  
SUN-CHUL HUH ◽  
JONG-SEOK LEE ◽  
GWI-NAM KIM ◽  
WON-JO PARK ◽  
JOUN-SUNG PARK ◽  
...  

Today, ships and structures are becoming larger (large structures, vessels, FPSO, etc.). Thus, high-strength welding material is required. The advantages of welding over other joining methods, depending on the development of welding technology, include such things as ease of operation and the structures of simplification and the confidential excellence, etc. However, shrinkage and deformation also occur, because of the repeated heating and cooling. Welding residual stress has an adverse effect on stability, but, it was closely related fatigue strength and brittle fracture of structures. In this study, experimental and analysis were conducted, and AIS3000 used to measure residual stress, which were compare with ANSYS analysis results. Metal surface microstructure was observed at various weld spots, as well as HAZ, and base metal using the optical microscope, and component analysis and crystal plane were measured using an XRD and EPMA.


2012 ◽  
Vol 557-559 ◽  
pp. 1304-1307 ◽  
Author(s):  
Jing Qiang Zhang ◽  
Jian Guo Yang ◽  
Jia Jie Wang ◽  
Xue Song Liu ◽  
Zhi Bo Dong ◽  
...  

Based on the estimation of the critical hydrogen pressure and concentrations required for hydrogen-induced delayed cracking in high-strength steel, the conclusion that welded joints are hydrogen pressure microcracks body can be drawn under certain conditions. Through the analysis of the relationship between the microstructure evolution of welded joints, diffusion enrichment of hydrogen and cracking behavior, the formation mechanism of hydrogen-induced delayed cracking in weld center of high-strength steel joints is analyzed and the mechanism that stress induced the residual diffusion hydrogen gathered to promote the hydrogen pressure microcracks propagation is proposed. The research shows that the initation and propogation of hydrogen-induced delayed cracking in weld center can be divided into two stages, i.e. irreversible hydrogen damage stage and reversible hydrogen damage stage. In irreversible stage hydrogen pressure is the main causes of the initation of microcracks, while in reversible stage welding residual stress and residual diffusible hydrogen are necessary conditions for microcracks growth. The microcracks growth can be controlled by regulating welding residual stress.


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