Numerical Simulation of Residual Stresses due to Multipass Welding in High Strength Steel Plates and Validation against Experimental Measurements

2018 ◽  
Vol 941 ◽  
pp. 269-273
Author(s):  
Constant Ramard ◽  
Denis Carron ◽  
Philippe Pilvin ◽  
Florent Bridier

Multipass arc welding is commonly used for thick plates assemblies in shipbuilding. Sever thermal cycles induced by the process generate inhomogeneous plastic deformation and residual stresses. Metallurgical transformations contribute at each pass to the residual stress evolution. Since residual stresses can be detrimental to the performance of the welded product, their estimation is essential and numerical modelling is useful to predict them. Finite element analysis of multipass welding of a high strength steel is achieved with a special emphasis on mechanical and metallurgical effects on residual stress. A welding mock-up was specially designed for experimental measurements of in-depth residual stresses using contour method and deep hole drilling and to provide a simplified case for simulation. The computed results are discussed through a comparison with experimental measurements.

2014 ◽  
Vol 996 ◽  
pp. 755-760 ◽  
Author(s):  
Bilal Ahmad ◽  
Michael E. Fitzpatrick

Fatigue cracks mostly initiate at areas subjected to high tensile residual stress and stress concentration. Ultrasonic peening is a mechanical method to increase fatigue life by imparting compressive residual stress. In this study residual stresses are characterized in fillet welded ship structural steel plates with longitudinal attachments. As-welded, ultrasonically peened, and specimens peened then subjected to accelerated corrosion testing were measured. Residual stress characterization was performed by the contour method and neutron diffraction.


Author(s):  
Gang Zheng ◽  
Sayeed Hossain ◽  
Feng Shen ◽  
Chris Truman

The aim of the present study was to utilize a complex residual stress generated within a welded circular disc to further investigate the standard deep-hole drilling (DHD) technique and the newly developed over-coring deep-hole drilling (oDHD) technique in accurately measuring residual stresses well over yield stress. Finite Element Analysis (FEA) was used to optimize and extend the deep-hole drilling technique and improve its accuracy. The standard DHD procedure involves 4 steps. (1) A reference hole is gun-drilled through the component. (2) The internal diameter of the reference hole is measured at different angular positions through the depth of the component. (3) A cylindrical section with the reference hole as its longitudinal axis is trepanned free from the component. (4) Finally, the relaxed internal diameter is re-measured at the same angular positions and the same depths. The drilling, trepanning procedures and the parameters of the deep-hole drilling technique were all studied in detail to optimize the technique. Comparison is made between the FEA predicted residual stress in the weld, the measurements and the reconstructed residual stresses of the measurements. The close correlations confirmed the suitability of new modifications made in the deep-hole drilling technique to account for plasticity when measuring near yield residual stresses present in a component.


2013 ◽  
Vol 768-769 ◽  
pp. 79-86 ◽  
Author(s):  
Horst Brünnet ◽  
Dirk Bähre ◽  
Theo J. Rickert ◽  
Dominik Dapprich

The incremental hole-drilling method is a well-known mechanical measurement procedure for the analysis of residual stresses. The newly developed PRISM® technology by Stresstech Group measures stress relaxation optically using electronic speckle pattern interferometry (ESPI). In case of autofrettaged components, the large amount of compressive residual stresses and the radius of the pressurized bores can be challenging for the measurement system. This research discusses the applicability of the measurement principle for autofrettaged cylinders made of steel AISI 4140. The residual stresses are measured after AF and after subsequent boring and reaming. The experimental residual stress depth profiles are compared to numerically acquired results from a finite element analysis (FEA) with the software code ABAQUS. Sample preparation will be considered as the parts have to be sectioned in half in order to access the measurement position. Following this, the influence of the boring and reaming operation on the final residual stress distribution as well as the accuracy of the presented measurement setup will be discussed. Finally, the usability of the FEA method in early design stages is discussed in order to predict the final residual stress distribution after AF and a following post-machining operation.


2014 ◽  
Vol 887-888 ◽  
pp. 924-928 ◽  
Author(s):  
Shu Qi Li ◽  
Hong Yuan Fang ◽  
Xuesong Liu

Welded components of DH36 low alloy high strength steel are widely used in offshore oil platforms and ships building. Stress reliving treatments to these welded components is of great importance. Vibration stress relief (VSR) method is an novel technology to release stress in welded components. In this study, 10×200×1000mm DH 36 steel plates were welded and then treated by VSR for about 1 hour. After the treatment, the residual stress was decreased by 29-72% at the welded toe, where the highest residual stress occurs. The metallographic microstructure of the joint was not changed by VSR. Investigation by transmission electron microscope (TEM) revealed that the amount of dislocations was increased at the welded toe. We hope this study can provide theoretical and practical fundamentals for widespread application of VSR on welded offshore engineering components.


Author(s):  
Xavier Ficquet ◽  
Vincent Robin ◽  
Ed Kingston ◽  
Stéphan Courtin ◽  
Miguel Yescas

This paper presents results from a programme of through thickness residual stress measurements and finite element analysis (FEA) modelling carried out on a temper bead mock-up. Emphasis is placed on results comparison rather than the measurement technique and procedure, which is well documented in the accompanying references. Temper bead welding processes have been developed to simulate the tempering effect of post-weld heat treatment and are used to repair reactor pressure vessel components to alleviate the need for further heat-treatment. The Temper Bead Mock-up comprised of a rectangular block with dimension 960mm × 189mm × 124mm was manufactured from a ferritic steel forged block with an austenitic stainless steel buttering and a nickel alloy temper bead cladding. The temper bead and buttering surfaces were machined after welding. Biaxial residual stresses were measured at a number of locations using the standard Deep-Hole Drilling (DHD) and Incremental DHD (iDHD) techniques on the Temper Bead Mock-up and compared with FEA modelling results. An excellent correlation existed between the iDHD and the modelled results, and highlighted the need for the iDHD technique in order to account for plastic relaxation during the measurement process. Maximum tensile residual stresses through the thickness were observed near the austenitic stainless steel surface at 298MPa. High compressive stresses were observed within the ferritic base plate beneath the bimetallic interface between austenitic and ferritic steels with peak stresses of −377MPa in the longitudinal direction.


2012 ◽  
Vol 726 ◽  
pp. 125-132 ◽  
Author(s):  
Aleksander Karolczuk ◽  
Krzysztof Kluger ◽  
Mateusz Kowalski ◽  
Fabian Żok ◽  
Grzegorz Robak

The main aim of the paper is determination of residual stresses in explosively welded steel-titanium bimetal. The analysis considers two bimetallic specimens: before and after the heat treatment. In residual stress determination the hole drilling method along with finite element analysis were applied. The results show different residual stress states depending on the heat treatment. The obtained results are confirmed by thermal stress calculation.


2016 ◽  
Vol 32 (14) ◽  
pp. 1449-1461 ◽  
Author(s):  
W. Guo ◽  
J. A. Francis ◽  
L. Li ◽  
A. N. Vasileiou ◽  
D. Crowther ◽  
...  

Author(s):  
R. J. Dennis ◽  
N. A. Leggatt ◽  
E. A. Kutarski

The ‘Contour Method’ is a relatively new relaxation method for residual stress measurement and may be seen as an evolution of established methods such as hole drilling. The general procedure when applying the Contour Method is cutting, measurement and calculation of residual stress normal to the cut plane using Bueckner’s principle of elastic superposition. That is the residual stresses are determined from the measured profile of a cut surface. While the Contour Method is simple in concept there are certain underlying issues relating to the cutting process that may lead to uncertainties in the measured results. Principally the issues are that of constraint and plasticity during the cutting process and the influence that they have on the measured residual stresses. Both of these aspects have been investigated in previous work by simulating the entire contour measurement method process using finite element techniques for ‘simple’ flat plate welded specimens. Here that work is further investigated and extended by application to a 316 Stainless Steel welded pipe structure containing a part-circumferential repair. This more complex structure and residual stress field is of significantly greater engineering interest. The key objective of this work is to ascertain the feasibility of and further our understanding of the performance of the Contour Method. Furthermore this work has the potential to provide a method to support the optimisation of the contour measurement process when applied to more complex engineering components.


Author(s):  
Eugene S. Statnik ◽  
Fatih Uzun ◽  
Svetlana A. Lipovskikh ◽  
Sviatoslav I. Eleonsky ◽  
Vladimir S. Pisarev ◽  
...  

SLM Additive Manufacturing has demonstrated great potential for aerospace applications when structural elements of individual design and/or complex shape need to be promptly supplied. 3D-printable AlSi10Mg (RS-300) alloy is widely used for the fabrication of different structures in aerospace industry. The importance of the evaluation of residual stresses that arise as a result of complex 3D-printing process thermal history is widely discussed in literature, but systematic assessment remains lacking for their magnitude, spatial distribution, and comparative analysis of different evaluation techniques. In this study we report the results of a systematic study of residual stresses in a 3D-printed double tower shaped samples using several approaches: the contour method, blind hole drilling laser speckle interferometry, X-ray diffraction, and Xe pFIB-DIC micro-ring-core milling analysis. We show that a high level of tensile and compressive residual stresses is inherited from SLM 3D-printing and retained for longer than 6 months. The stresses vary over a significant proportion of the material yield stress. All residual stress evaluation techniques considered returned comparable values of residual stresses even regardless of dramatically different dimensional scales from millimeters for the Contour Method down, laser speckle interferometry and XRD and down to small fractions of a mm (70 μm) for Xe pFIB-DIC ring-core drilling. The use of residual stress evaluation is discussed in the context of optimizing the printing strategy to enhance the mechanical performance and long-term durability.


2011 ◽  
Vol 681 ◽  
pp. 177-181 ◽  
Author(s):  
Valentin Richter-Trummer ◽  
Pedro Miguel Guimarães Pires Moreira ◽  
João Ribeiro ◽  
Paulo Manuel Salgado Tavares de Castro

Residual stresses parallel to the welding direction on a cross-section of a 3 mm thick friction stir butt-welded aluminum alloy AA6082-T6 plate were determined using the contour method. A full contour map of longitudinal residual stresses on a weld cross section was determined in this way, revealing detailed information on the residual stress distribution in the inside of a friction stir weld, especially in the nugget zone. The typical M-shape, usually described for the residual stress distribution in friction stir welds, was found. The maximum residual stresses are below the yield strength of the material in the shoulder region and, outside of the welding region, low tensile and compressive residual stresses are responsible for the necessary stress equilibrium on the plane of interest. A comparison was made with the established incremental hole drilling technique on an equivalent plate for validation and good agreement of both techniques was obtained. The distribution, as well as the magnitude of the residual stresses measured by both techniques, is very similar, thus validating both the experimental and numerical procedures used for the contour method application, presented and discussed in the present paper.


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