G030034 Residual Stress Measurement of Large-Bore Nuclear Pipe with Weld Joint by Inherent Strain Method

2011 ◽  
Vol 2011 (0) ◽  
pp. _G030034-1-_G030034-4
Author(s):  
Akira MAEKAWA ◽  
Keiji NAKACHO ◽  
Norifumi KASAHARA ◽  
Keisuke AOKI
Keyword(s):  
Residual Stress ◽  
Weld Joint ◽  
Stress Measurement ◽  
Residual Stress Measurement ◽  
Inherent Strain ◽  
Inherent Strain Method ◽  
Strain Method

Research on Deformation Prediction Method of Laser Melting Deposited Large-Sized Parts Based on Inherent Strain Method

2021 ◽  
Vol 871 ◽  
pp. 65-72
Author(s):  
Cheng Hong Duan ◽  
Xian Kun Cao ◽  
Ming Huang Zhao ◽  
Xiang Peng Luo
Keyword(s):  
Residual Stress ◽  
Laser Energy ◽  
Layer By Layer ◽  
Laser Melting ◽  
Forming Process ◽  
Deformation Prediction ◽  
Metal Parts ◽  
Inherent Strain ◽  
Inherent Strain Method ◽  
Strain Method

In the process of metal parts fabricated by Laser Melting Deposition (LMD), a high temperature gradient will generate due to the instantaneous high laser energy input, which will cause residual stress in the formed part of metal parts, the residual stress will result in defects like warping deformation or even cracking. In this paper, a finite element method based on inherent strain method is proposed to predict the deformation of metal parts fabricated by LMD. Firstly, combing with the birth and death element technology, a local model is established to simulate the layer-by-layer deposition in the LMD forming process, and the values of inherent strain is obtained. Secondly, the obtained inherent strain values is applied to large-sized part layer by layer, and the final deformation of large-sized part is calculated. Based on the proposed method, the efficiency of deformation prediction of large-sized metal parts fabricated by LMD could be effectively improved.

Residual Stress Evaluation of Dissimilar Weld Joint Using Mock-Up Models of Bottom Mounted Instrument Nozzle

2013 ◽  
Author(s):  
Naoki Ogawa ◽  
Kiminobu Hojo ◽  
Hiroaki Shirako ◽  
Takehiko Sera
Keyword(s):  
Residual Stress ◽  
Weld Joint ◽  
Circumferential Stress ◽  
Strain Gauges ◽  
Analysis Method ◽  
Stress Evaluation ◽  
Dissimilar Weld ◽  
Dominant Component ◽  
Inherent Strain ◽  
Inherent Strain Method

In this paper benchmark analyses was performed to evaluate the accuracy of the FE analysis method for estimating residual stress of a dissimilar weld joint of a bottom mounted instrument (BMI) nozzle. The analyses simulated each fabrication and operational process of the weld joint nozzle. For confirmation of calculation accuracy a mock-up models of BMI nozzle were produced using the same fabrication process in Japanese PWR plants and the stress distribution of the model was measured using inherent strain method. From the limitation of the geometry of the BMI nozzle smaller strain gauges were applied to decrease the measurement error. As a result a better agreement between the calculation and measurement was obtained than that of the former investigation and the circumferential stress is confirmed dominant component in the weld region.

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