Modelling and Measuring Residual Stresses in Pipe Girth Welds: Lessons From the Style Framework 7 Project

2014 ◽  
Author(s):  
Mike C. Smith ◽  
Ondrej Muransky ◽  
David Smith ◽  
Son Cao Do ◽  
P. John Bouchard ◽  
...  
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Measurement Techniques ◽  
Simulation Techniques ◽  
Element Simulation ◽  
Weld Residual Stress ◽  
Wide Range ◽  
Girth Welds ◽  
Welded Pipe ◽  
Stress Simulation

A number of girth-welded pipe mock-ups have been manufactured and investigated during the STYLE project, using a wide range of measurement techniques accompanied by extensive finite element simulation campaigns. This paper gives an overview of the work carried out and presents preliminary conclusions on the performance of finite element weld residual stress simulation techniques in the different mock-up designs.

Development of a Residual Stress Simulation Benchmark for a Single Bead-on-Plate Weldment

2006 ◽  
Author(s):  
Peter J. Bouchard ◽  
Lyndon Edwards ◽  
Anastasius G. Youtsos ◽  
Roger Dennis
Keyword(s):  
Residual Stress ◽  
Assessment Procedure ◽  
Defect Assessment ◽  
Best Estimate ◽  
Weld Residual Stress ◽  
Single Bead ◽  
Stress Prediction ◽  
Stainless Steel Bead ◽  
Stress Simulation ◽  
Network Project

Finite element weld residual stress modelling procedures involve complex non-linear analyses where many assumptions and approximations have to be made by the analyst. Weld modelling guidelines for inclusion in the R6 defect assessment procedure are in preparation and will be accompanied by a series of validation benchmarks that can be used to evaluate the accuracy of weld modelling procedures and assess their suitability for use in fracture assessments. It is intended to base one of the benchmarks on a stainless steel bead-on-plate weldment that has been extensively studied by members of Task Group 1 of the NeT European Network project. This paper uses round robin residual stress measurements from the NeT project to derive a statistically based ‘best estimate’ distribution of transverse stress passing through the wall-section at mid-length of the bead-on-plate weldment. The accuracy of a state-of-the-art residual stress prediction is benchmarked against the best estimate measurements using a root mean square error analysis and comparisons of decomposed components of stress. The appropriateness of using the predicted residual stresses in fracture assessments is assessed by comparing stress intensity factors based on the measured and predicted distributions of stress. The results from these studies will be used to help establish accuracy targets and acceptance criteria for the welding benchmark.

Study on Welding Deformation and Residual Stress of H-Section Beam Based on Finite Element Method

2017 ◽  
Vol 753 ◽  
pp. 305-309 ◽  
Author(s):  
Xu Lu
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Finite Element ◽  
Source Parameters ◽  
Welding Process ◽  
Steel Structure ◽  
Bottom Plate ◽  
Welding Deformation ◽  
Element Simulation ◽  
Main Components

The welding H-section beam has good mechanical properties with its superior structure. So they become the main components of steel structure and have been widely used. In this paper, the welded H-section beam is used as the research object. The finite element simulation model is established. The heat source parameters are determined. The deformation of the steel due to the welding process is studied. The results show that the bottom plate and the bottom plate inward bending is about 2.32mm cause by welding process. The residual stress can reach 400MPa.

scholarly journals Residual Stress State of X65 Pipeline Girth Welds Before and After Local and Furnace Post Weld Heat Treatment

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Yao Ren ◽  
Anna Paradowska ◽  
Bin Wang ◽  
Elvin Eren ◽  
Yin Jin Janin
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Residual Stresses ◽  
Outer Surface ◽  
Post Weld Heat Treatment ◽  
Pipe Length ◽  
Stress Profiles ◽  
Girth Welds ◽  
Welded Pipe ◽  
Weld Heat

This research investigated the effects of global (in other words, furnace-based) and local post weld heat treatment (PWHT) on residual stress (RS) relaxation in API 5L X65 pipe girth welds. All pipe spools were fabricated using identical pipeline production procedures for manufacturing multipass narrow gap welds. Nondestructive neutron diffraction (ND) strain scanning was carried out on girth welded pipe spools and strain-free comb samples for the determination of the lattice spacing. All residual stress measurements were carried out at the KOWARI strain scanning instrument at the Australian Nuclear Science and Technology Organization (ANSTO). Residual stresses were measured on two pipe spools in as-welded condition and two pipe spools after local and furnace PWHT. Measurements were conducted through the thickness in the weld material and adjacent parent metal starting from the weld toes. Besides, three line-scans along pipe length were made 3 mm below outer surface, at pipe wall midthickness, and 3 mm above the inner surface. PWHT was carried out for stress relief; one pipe was conventionally heat treated entirely in an enclosed furnace, and the other was locally heated by a flexible ceramic heating pad. Residual stresses measured after PWHT were at exactly the same locations as those in as-welded condition. Residual stress states of the pipe spools in as-welded condition and after PWHT were compared, and the results were presented in full stress maps. Additionally, through-thickness residual stress profiles and the results of one line scan (3 mm below outer surface) were compared with the respective residual stress profiles advised in British Standard BS 7910 “Guide to methods for assessing the acceptability of flaws in metallic structures” and the UK nuclear industry's R6 procedure. The residual stress profiles in as-welded condition were similar. With the given parameters, local PWHT has effectively reduced residual stresses in the pipe spool to such a level that it prompted the thought that local PWHT can be considered a substitute for global PWHT.

On the Mechanics of Residual Stresses in Girth Welds

2006 ◽  
Vol 129 (3) ◽  
pp. 345-354 ◽  
Author(s):  
P. Dong
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Relative Importance ◽  
Stress Distributions ◽  
Unified Framework ◽  
Joint Geometry ◽  
Weld Residual Stress ◽  
Girth Welds ◽  
Welding Procedure

In this paper, some of the important controlling parameters governing weld residual stress distributions are presented for girth welds in pipe and vessel components, based on a large number of residual stress solutions available to date. The focus is placed upon the understanding of some of the overall characteristics in through-wall residual stress distributions and their generalization for vessel and pipe girth welds. In doing so, a unified framework for prescribing residual stress distributions is outlined for fitness-for-service assessment of vessel and pipe girth welds. The effects of various joint geometry and welding procedure parameters on through thickness residual stress distributions are also demonstrated in the order of their relative importance.

Modeling and Prediction of Residual Stresses in Additive Layer Manufacturing by Microplasma Transferred Arc Process Using Finite Element Simulation

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Sagar H. Nikam ◽  
N. K. Jain
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Temperature Distribution ◽  
Residual Stresses ◽  
Substrate Material ◽  
Tensile Residual Stress ◽  
Additive Layer Manufacturing ◽  
Element Simulation ◽  
Layer Manufacturing ◽  
Transferred Arc

Prediction of residual stresses induced by any additive layer manufacturing process greatly helps in preventing thermal cracking and distortion formed in the substrate and deposition material. This paper presents the development of a model for the prediction of residual stresses using three-dimensional finite element simulation (3D-FES) and their experimental validation in a single-track and double-track deposition of Ti-6Al-4V powder on AISI 4130 substrate by the microplasma transferred arc (µ-PTA) powder deposition process. It involved 3D-FES of the temperature distribution and thermal cycles that were validated experimentally using three K-type thermocouples mounted along the deposition direction. Temperature distribution, thermal cycles, and residual stresses are predicted in terms of the µ-PTA process parameters and temperature-dependent properties of substrate and deposition materials. Influence of a number of deposition tracks on the residual stresses is also studied. Results reveal that (i) tensile residual stress is higher at the bonding between the deposition and substrate and attains a minimum value at the midpoint of a deposition track; (ii) maximum tensile residual stress occurs in the substrate material at its interface with deposition track. This primarily causes distortion and thermal cracks; (iii) maximum compressive residual stress occurs approximately at mid-height of the substrate material; and (iv) deposition of a subsequent track relieves tensile residual stress induced by the previously deposited track.

Sign in / Sign up

Export Citation Format

Share Document