Circular Section Research Articles

Axial compressive behaviors of multi-cavity concrete-filled double-skin tubular stub columns

The axial compressive behaviors of multi-cavity concrete-filled double-skin steel tubular (MCFDST) stub columns are investigated using experimental and numerical methods in this study. The MCFDST columns comprise two concentric steel tubes (circular hollow section (CHS) inner and square hollow section (SHS) outer), sandwiched concrete filled between them, and four strips connecting outer and inner tubes. Fourteen MCFDST stub columns and two concrete-filled double-skin steel tubular (CFDST) (CHS inner and SHS outer) stub columns are fabricated and tested. Experimental results are used to validate the accuracy of finite element models of MCFDST and CFDST stub columns, and based on which, extensive parameter analyses are conducted. The analysis results show that the strips delay the local buckling and change the buckling mode of outer steel tube, as well as improve the bearing capacity and ductility of stub columns. Observed failure modes are controlled by the local buckling of the outer tube associated with the crushing of filled concrete. In addition, the axial compressive performance of MCFDST stub columns can be improved by reducing the width-to-thickness ratio of outer tube, increasing the steel yield strength of outer tube and concrete strength, and adding strips. The hollow ratio has a negligible effect on the axial compressive behaviors when it ranges from 0.26 to 0.56. Furthermore, the predicted results by European, Japanese, British, and Chinese codes are compared with the experimental and FE results, suggesting that the formula in the European code has the best accuracy when predicting the load-bearing capacity of MCFDST stub columns.

Design and Implementation of Sampling Wells in Phosphate Mine Waste Rock Piles: Towards an Enhanced Composition Understanding and Sustainable Reclamation

Establishing a circular economy in mining begins with a dedicated sampling strategy as its fundamental phase. This specific approach is crucial for enhancing resource retrieval and isolating essential minerals from mining residues. By carefully examining and defining the makeup of waste materials, mining activities can discover overlooked possibilities, promoting sustainability. A thoughtfully planned sampling strategy not only reduces environmental harm but also sets the stage for the effective use of resources. In doing so, the mining industry can shift towards a circular model, adhering to the principles of waste reduction, material reuse, and ultimately promoting a more environmentally conscious and economically viable industry. In the phosphate industry and during the pre-concentration process of phosphate ore through screening, significant amounts of mining waste, consisting of various lithologies including indurated and fine phosphate, coarse-grained silicified phosphate, limestone, and marls, are deposited in waste rock stockpiles. Collecting representative samples from these heterogeneous materials presents challenges in accurately characterizing the entire stockpile. To overcome this issue, circular mining wells were implemented as a novel sampling method in waste rock stockpiles, enabling the collection of intact representative samples. This paper shares a successful experience in constructing three concrete-lined wells within a phosphate mine waste rock stockpile measuring 662 m in length, 240 m in width, and ranging in height from 0 to 65 m. The wells were dug at various depths, ranging from 20 m to 55 m, with a circular section and a diameter of 1.5 m. An integrated method utilizing analytical techniques in conjunction with numerical modeling via Robot Structural Analysis software (version of 2020) was utilized to assess the stress on the well supports and confirm their stability. This methodology serves as a valuable tool for evaluating the stability of similar wells, ensuring the safety of operators. The structural model yielded a stress level of 1 MPa, which aligned with the values obtained from the analytical model. Sensitivity analysis was performed on various parameters (friction angle, Poisson Ratio, and gravity), and the safety factor consistently remained above 1.5 for all scenarios investigated up to a depth of 60 m. Consequently, this study demonstrates that concrete-lined wells can be utilized safely for intact sampling in waste rock stockpiles. This sampling operation will allow the pursuit of optimizing resource utilization and enhancing environmental sustainability, by studying phosphate distribution in the Phosphate Mine Waste Rock (PMWR) for better recovery.

Experimental study of concrete-filled stainless steel tubular stub columns with circular and square cross-sections subjected to combined compression and bending

This paper presents an experimental study into the structural behaviour and strength of concrete-filled stainless steel tubular stub columns with circular and square cross-sections subjected to combined compression and bending moment. A total of sixteen concrete-filled stainless steel tubular (CFSST) stub columns were tested, including two section types (circular and square hollow sections), two grades of concrete infill (C30 and C60), two thicknesses of tube wall for each cross-section (6 and 10 mm), and five loading eccentricity ratios (0, 0.2, 0.3, 0.4 and 0.5). The CFSST stub column specimens were loaded in compression, with different loading eccentricities applied to achieve a wide range of axial load-to-bending moment ratios. This research provides a comprehensive report on the experimental methodology and subsequent observations, including the failure modes, load-deformation curves, axial load-bending moment curves, strain development at the key locations and values of ductility index. It can be observed that for circular CFSST columns, ultimate load decreased by roughly 70% with an increase in loading eccentricity ratios from 0 to 0.5, while for square columns, the reduction was about 50% under same conditions. The experimental results were used to evaluate if the existing design provisions for carbon steel-concrete composite structures is capable of designing the investigated CFSST stub columns. It was found that the mean ultimate load to predicted failure load ratios are 1.25, 1.32, and 1.36, with coefficients of variations (COV) equal to 0.08, 0.09 and 0.11, for the European, American, and Chinese codes, respectively. Consequently, the design approach specified in the Chinese code led to the most conservative and scattered strength predictions among the three codified design approaches. In contrast, the European code provides the most precise predictions of the test results, though there still remains scope for improvements in the ultimate resistance predictions of CFSST stub columns subjected to combined compression and bending.

Brazilian savannah tree as bio-inspiration for hydraulic transient control in a penstock of a small hydropower plant

This study proposes an innovation, which is to use a non-circular and bio-inspired forced conduit (a new penstock with a cross section inspired by a tree trunk), to control the effects of hydraulic transients in Brazilian small hydropower plants (SHPs). The aim is to demonstrate that natural structures, adapted to periodic environmental disturbances, are better at hydraulic transient control than traditional conduits. The proposed methodology includes the following steps: (1) problem identification; (2) potential biological model identification; (3) development of alternatives; (4) implementation and testing; and (5) solution selection. This research was conducted at the São Tadeu I SHP, in the city of Santo Antônio de Leverger/MT, Brazil. The following tree biological models from the Brazilian savannah (Cerrado) were used: Handroanthus capitatus and Strychnos pseudoquina. The proposed innovation improves the conduit of the traditional circular section and the relief valve solution of the criteria studied. The reason for this improvement was the reduction of wave speed in the non-circular section (from 1126 to 583 m s−1).

Method and experimental study of strengthening circular hollow section T-joints by partial filling with cementitious materials

Circular hollow section truss joints may need to be strengthened for various reasons. This study evaluated a new method for strengthening such joints by partially filling the chords with cementitious materials, including grout and mortar. Taking T-joints as an example, the proposed strengthening process was described and experiments were conducted on six joints (four strengthened and two unstrengthened) under axial compression or tension applied to the braces. The failure modes and structural behaviors of the joints before and after strengthening were compared, and the effects of the strengthened length, filling material, direction of brace loading, and presence of temporary openings in the chord on the performance of the T-joints were investigated. The results demonstrated that: the strengthening method was viable and effective, the T-joint filled with 1d0 grout (mortar) exhibited a 70% (33%) improvement in initial stiffness and a 50% (36%) improvement in ultimate loading capacity; the use of grout was more efficient and convenient for construction than mortar; the initial stiffness and ultimate loading capacity of the strengthened T-joint was also improved when the brace were under tension; the temporary openings cut in the chord during the strengthening process had a little effect on the performance of the T-joint, with reductions of 11% and 9% in initial stiffness and ultimate loading capacity, respectively. Thus, the performance and safety of the joints can be ensured if reasonable design and protection measures are implemented.

Experimental study of the vortex-induced vibration of a circular cylinder considering coupling effect in along- and across-wind direction

Tower-like structures with circular section are prone to unexpected across-wind vortex-induced vibration (VIV), and the along-wind response is usually neglected due to its amplitude being much smaller than that of VIV. Recent research pertaining to tall buildings has revealed, nevertheless, that the structural responses in the along-wind and across-wind directions are coupled in a way that results in a decrease in the across-wind response at the wind speed of VIV along with an increased along-wind response. However, the impact of coupling on tower-like structures has not yet been examined. Moreover, tower-like structures with a circular cross section undergo tip-induced vibration at the wind speed higher than vortex-resonance wind speed. However, the impact of this coupling effect on the tip-induced vibration remains uncertain. In this paper, a two-degree-of-freedom rocking model wind tunnel test is carried out under low turbulence and turbulent flow to investigate the coupling effect of tower-like structures. Experiment results show that the coupling effect exists at both the vortex-resonance vibration wind speed and the tip-induced vibration wind speed. Besides, when the along-wind response is coupled with the across-wind responses, it illustrates a steady harmonic vibration with a hardened non-Gaussian characteristic, and its kurtosis decreases to 1.5. Finally, the measured tip-associated vortex shedding frequency suggests that there is a “lock-in” phenomenon of the tip-induced vibration, this new finding improves the understanding of the wind-induced response at high wind speeds.

Structural design and particle size examination on NiO-CeO2 catalysts supported on 3D-printed carbon monoliths for CO2 methanation

3D-printed high-surface carbon monoliths have been fabricated and tested as catalyst supports of CO2 methanation active phases (NiO-CeO2, 12 wt% Ni). The carbon carriers show a developed microporosity and good adherence to the catalytic phases of NiO-CeO2, showing great stability and cyclability. Two monolith designs were used: a conventional parallel-channeled structure (honeycomb) and a complex 3D network of non-linear channels built upon interconnected circular sections (circles), where flow turbulences along the reactant gas path are spurred. The effect of the active phases particle size on the catalyst distribution and the overall performance has been assessed by comparing NiO-CeO2 nanoparticles of 7 nm average (Np), with a reference counterpart of uncontrolled structure (Ref). The improved radial gases diffusion in the circles monolith design is confirmed, and nanoparticles show enhanced CO2 methanation activity than the uncontrolled-size active phase at low temperatures (< 300 ºC). On the contrary, the Ref catalysts achieve higher CH4 production at higher temperatures, where the reaction kinetics is controlled by mass transfer limitations (T > 300 ºC). SEM and Hg porosimetry evidence that nanoparticles are deposited at deeper penetration through the narrow micropores of the carbon matrix of the monolithic supports, which tend to accumulate on the channels surface remaining more accessible to the reactant molecules. Altogether, this study examines the impact of the channel tortuosity and the active phase sizing on the CO2 methanation activity, serving as ground knowledge for the further rational and scalable fabrication of carbon monolith for catalytic applications.

Estimating π Using the Topography of the Terrestrial Planets

AbstractIt is π‐day 2024 (March 14th) and to celebrate, we ask the question: can π be estimated accurately using the shape of the terrestrial planets and the Moon? We proceed by using models for the planet topographies in slices of constant latitude and computing π as the ratio of the circumference to the diameter in each slice. We define the circumference as the topographically undulating perimeter of the slice (which deviates from the circular section of the reference ellipsoid). We define the diameter as the distance connecting two opposite points on the topography model through the center of the slice. This gives us a distribution of π estimates for each latitude slice and overall for each planetary body. The distribution and accuracy of the π estimates we compute are a representation of how smooth and circular latitude slices of the terrestrial planets are. We find that Mercury and Venus are particularly good at predicting π because they are relatively smooth and the topographic deviations from the reference ellipsoid are small compared with Mars, Earth, and the Moon. In the spirit of π‐day, this mathematical exercise motivates an interest in planetary geophysics and shape.

A three-dimensional flow-electrochemistry coupling model for optimizing the channel configuration of lithium slurry redox flow battery

Lithium slurry redox flow batteries (SRFBs) are a promising candidate for scalable energy storage systems. The section is one of the most basic elements of the flow field. The battery performance optimization based on the section reconstruction is helpful to improve the flow distribution of active particle suspensions in flow channel, reduce the edge slurry retention, and enhance the reaction uniformity. Here, a three-dimensional numerical model of SRFB is established, and its accuracy is verified by experiments. Through multiphysics field simulation, it is proved that the rectangular section is more suitable for SRFB than the triangular and circular sections for the flow channels, but the velocity distribution is elliptical and decreases along the surrounding edge area. Such a rectangular section reconfiguration, which conforms to the velocity distribution characteristics of the slurry, is beneficial to improve the speed of the slurry edge and promote the overall uniform distribution of the slurry. Specifically, the top-arc bottom rectangular design (A1) demonstrates the best comprehensive performance. The influence of flow rates on the slurry distribution is examined. The results show that the slurry has a relatively low pressure drop and a more uniform distribution when the inlet flow rate is approximately 30 ml min−1.

Numerical analysis and design methods of grout-filled GFRP tube repaired corroded CHS T-joints

This study explores the compressive behavior of Grout-Filled GFRP Tube (GFGT) repaired corroded circular hollow section (CHS) T-joints. Finite element models of GFGT repaired corroded joints were developed, validated, and utilized to examine the influence of the joint geometric, material, and chord end stress parameters on the compressive strength and repairing efficiency of the joints. The findings reveal that the ultimate strength of the GFGT repaired joint increases with a thicker GFRP tube, a lower repaired chord section hollow ratio, a higher grout strength, and a longer repaired range. By optimizing the repairing parameters of the grout-filled GFRP tube, the compressive strength of GFGT repaired corroded joints with 16% and 32% corrosion rates can be up to increase to 164% and 147% of the uncorroded counterparts, respectively. The chord end stress exerts a similar but weaker effect on the repaired joints than on the unrepaired joints. A series of suggestions were proposed for repairing joints with different corrosion degrees to achieve a 20% ultimate strength enhancement compared to uncorroded joints. The compressive strength degradation rate of corroded joints was accurately predicted by the design method in the CIDECT and prEN guidelines. The feasibility of the guideline formulae to evaluate the strength reduction rate caused by the chord end preload was verified. A design method to predict the compressive strength of GFGT repaired corroded joints was proposed.

Comparative research on the pipe-soil frictional resistances of circular and rectangular pipe sections during trenchless pipe jacking.

Pipe jacking is a trenchless construction method to achieve forward tunneling and efficient construction of underground structure simultaneously without extensive surface excavation. In the process of pipe jacking construction, the jacking force provided by the hydraulic jacking equipment must overcome the frontal resistance of the cutter head and the frictional resistance between the pipe sections and formation at the same time. In particular, the pipe-soil frictional resistance increases with the increases of jacking distance, buried depth, pipe diameter and the complexity of jacking trajectory. Therefore, it is very important to correctly estimate jacking force in trenchless jacking engineering practice for the smooth implementation of pipe jacking, operation risk and comprehensive cost control. Firstly, the stress states of jacking circular and rectangular pipe sections in the soil are analyzed, and the key influencing factors of their pipe-soil frictional resistance are obtained respectively. Then, the pipe-soil frictional resistance of jacking the circular and rectangular pipe sections with the same external surface area in the dry sandy soil and coal granular layer are tested separately by using the self-developed multifunctional experimental apparatus during trenchless pipe jacking. The results show that the pipe-soil frictional resistances of jacking circular and rectangular pipe sections in the coal granular layer are always smaller than that in the sandy soil under the same experimental conditions, and the corresponding fitting calculation equation of pipe-soil frictional resistances are obtained respectively. Meanwhile, the modified calculation methods of the above pipe-soil frictional resistances are proposed respectively based on the relationship between the lateral pressure coefficient K and the buried depth of pipe section H. Moreover, the disturbed area of soil in the upper part of jacking circular pipe section presents an arc distribution, while the disturbed area of soil in the upper part of jacking rectangular pipe section presents a slightly concave distribution. Due to the different disturbance conditions of soil around the pipe section, the lateral pressure coefficient K should be corrected in the calculation equations of pipe-soil frictional resistance of jacking circular and rectangular pipe sections based on the discrete element numerical simulation analysis by EDEM software. Finally, the pipe-soil frictional resistances obtained by different methods in the sandy soil are compared and analyzed. The calculated values of the modified theoretical calculation method are very close to the experimental test values, while the other methods are smaller than the experimental test values, which makes the rationality of the modified theoretical calculation method of pipe-soil frictional resistance is verified, and some suggestions are also put forward for the value of some coefficients in the relevant empirical estimation equations. The above research achievements systematically compared the states of pipe-soil frictional resistances of jacking circular and rectangular pipe sections based on different research methods, especially for the correct evaluation of jacking force during trenchless pipe jacking, they could provide some valuable references and effective guidance for the subsequent research, engineering practice and further development of trenchless pipe jacking technology.

Numerical Study on Steel Reinforced Concrete Filled Steel Tubular Columns of Circular and Square Sections Exposed to Fire

Numerical Study on Steel Reinforced Concrete Filled Steel Tubular Columns of Circular and Square Sections Exposed to Fire

Effect of the CFRP length and beam curvature on the strength gain of CFRP-strengthened vertically curved circular hollow sections: an experimental study

ABSTRACT The effects of CFRP wrapping length and the beam curvature on the ultimate strength of carbon fibre reinforced polymer (CFRP)-strengthened in-plane curved steel circular hollow sections (SCHS) were studied by means of an experimental study. A total of 16 beams having four curvatures 0 mm, 2000 mm, 4000 mm and 6000 mm, which were strengthened with three CFRP lengths 500 mm, 750 mm and 1000 mm, were tested under three-point bending. Failure loads, failure mechanisms, strain variations and load-deflection responses were observed. Four types of failure modes were observed in CFRP-strengthened vertically curved SCHS depending on the CFRP wrapping length. The best performance was noted in strengthened beams when the ratio between CFRP wrapping length and beam span is 0.625.

Parametric Study of Lateral Load on Helical Pipe Piles in Clay

In the past decades, as the world has placed emphasis on green energy, solar energy has become a favorable option. Different piled foundations have been designed to strengthen the structure supporting the solar panels. These piled foundations include rectangular and circular hollow section piles, as well as H-shaped piles. With various environmental loadings, lateral soil displacement will be encountered when large solar panels are installed on the supporting structure at an inclined angle. Presently, helical pipe piles are widely used in solar farms as part of the supporting structure. In this paper, the pile–soil interaction of steel pipe piles and helical pipe piles with wind loads is analyzed using ABAQUS. The Finite Element Method (FEM) models are assessed with varying strength moduli and cohesions of clay. Further, this paper examines the pile soil system, considering different clay stiffnesses, including very soft, soft, firm, stiff, very stiff, and hard. It is found that the helical piles’ horizontal capacity increases with soil strength and Young’s modulus, but the capacity increment rate reacts differently. This study has a guiding effect on the construction of solar farms using the “tracker” solar system.

Numerical simulation of corroded circular hollow section steel columns: A corrosion evolution approach

This study introduces a numerical simulation method for corroded circular hollow section steel columns, utilising a newly developed corrosion evolution model. This model was formulated by characterising the corrosion morphology and calibrating parameters throughout the entire corrosion process. An interpolation method was implemented to estimate the number of corrosion pits, based on experimentally measured corrosion ratios. Consequently, this allowed for the numerical prediction of the time-varying corrosion morphologies. Finite element (FE) models, incorporating this corrosion evolution model, were constructed. These corroded column models underwent validation through comparison with experimental findings. To further establish the effectiveness of the proposed FE models in predicting the structural behaviour of corroded members, FE models were also developed using the traditional uniform thickness reduction approach for comparative analysis. The results revealed that the proposed FE models for corroded structures offer a more accurate prediction of mechanical performance, particularly in instances of severe corrosion damage.

Calibration of Thixotropic and Viscoelastic Shear-Thinning Fluids Using Pipe Rheometer Measurements

Some non-Newtonian fluids have time-dependent rheological properties like a shear stress that depends on the shear history or a stress overshoot that is a function of the resting time, when fluid movement is started. The rheological properties of such complex fluids may not stay constant while they are used in an industrial process, and it is therefore desirable to measure these properties frequently and with a simple and robust device like a pipe rheometer. This paper investigated how the time-dependent rheological properties of a thixotropic and viscoelastic shear-thinning fluid can be extracted from differential pressure measurements obtained at different flowrates along a circular pipe section. The method consists in modeling the flow of a thixotropic version of a Quemada fluid and solving the inverse problem in order to find the model parameters using the measurements made in steady-state conditions. Also, a Maxwell linear viscoelastic model was used to reproduce the stress overshoot observed when starting circulation after a resting period. The pipe rheometer was designed to have the proper features necessary to exhibit the thixotropic and viscoelastic effects that were needed to calibrate the rheological model parameters. The accuracy of rheological measurements depends on understanding the effects that can influence the observations and on a proper design that takes advantage of these side effects instead of attempting to eliminate them.

Numerical Investigation of the Magnetohydrodynamic Mixed Convection inside an Extended Curved Duct in the Presence of a Nanofluid of Different Metallic Oxides Nanoparticles

The numerical work presented in this paper focuses on the influence of the magnetic field and the nanoparticles metallic nature on the hydrodynamic and thermal behavior of a nanofluid flowing in an extended curved duct. It deals with a semi-toroidal curved duct with an expanded circular section. The narrowed part of this duct from which the nanofluid enters with a cold temperature, is considered to be thermally insulated. However, the extended part is kept at a constant hot temperature. The nanoparticles used in the present study respectively are Alumina (Al2O3), copper oxide (CuO) and iron trioxide (Fe3O4). In this study, the effects of inertia, buoyancy and Lorentz forces as well as the metallic nature of the nanoparticles suspended in the pure water have been highlighted on the thermal, hydrodynamic and economic levels. The study is based on the resolution of the classical monophasic equations governing the non-isothermal flow of nanofluids by the use of finite element method, namely: the mass, momentum and energy equations. The obtained results have shown that the buoyancy and inertia forces strongly favor the global heat exchange rate. Moreover, the magnetic force acts negatively on these thermal exchanges. Furthermore, the CuO nanoparticles have demonstrated a better heat transfer rate, approximately 7% higher than that of pure water. Nevertheless, according to the economic needs, we suggest we suggest using alumina nanoparticles, as their transfer rate is comparable to that of CuO nanoparticles. It should be noted, that this study provides important insights for many industrial applications where the curved ducts are strongly presented.

S890 hot-rolled ultra-high strength steel (UHSS) seamless circular hollow section beam–columns: Testing, modelling and design

With the recent rapid development of manufacturing techniques and material science, advanced hot-rolling of ultra-high strength steel (UHSS) with material grades up to S890 becomes possible. The structural behaviour of S890 hot-rolled ultra-high strength steel (UHSS) seamless circular hollow section (CHS) beam–columns fabricated through the advanced manufacturing method, was investigated through testing and numerical modelling and reported in this paper. In the physical testing, a total of 12 beam–columns were firstly tested featuring the flexural buckling failure mode, with the material coupon tests and initial global geometric imperfection measurements performed. FE modelling was then conducted, where the FE models were developed and validated against the test observations. The validated FE models were then adopted in the parametric studies in a wider spectrum of member lengths, cross-section dimensions and loading combinations, resulting in the additional 300 FE data to be generated. Finally, the current design provisions, as set out in Eurocode, American specification and Australian standard, are assessed for their applicability to S890 hot-rolled UHSS seamless CHS beam–columns. It was revealed from the assessment results that the design provisions in three design codes can be accurately applied to S890 hot-rolled UHSS seamless CHS beam–columns.

Buckling and fracture behavior of cold formed carbon/stainless steel tubular braces under far field and near fault loadings

To date, many studies have been conducted on the experimental behaviors of circular and square hollow section braces. In those studies, the effect of material properties, cross-sectional shape and loading history on the performance of braces were investigated independently of each other. In this study, the effects of the combined actions of these variables on the performance of steel braces were examined. For this purpose, approximately 1/3 scaled 12 specimens (6 circular and 6 square), which were cold formed from carbon/stainless steel sheets, were experimentally and numerically investigated under 3 different cyclic load effects representing far field and near fault loadings. The buckling strength, energy dissipation capacity and displacement ductility of the specimens were evaluated. In addition, parametric studies, using 198 FE analyses verified with current study, were conducted. Experimental results indicate that the buckling strength limits provided in AISC 360–22 and EN 1993-1-1 for carbon steel braces are significantly influenced by the cross-section, loading protocol and material properties. On the other hand, it has been determined that the buckling strength limits given in AISC 370–21 and EN 1993-1-4 for stainless steel braces are safe for far field loadings, but insufficient for near fault loadings along the full slenderness range. It has been seen that the most disadvantageous results for the buckling strength, energy dissipation capacity and displacement ductility of the braces can only be obtained by applying different loading protocols. Moreover, It has been determined that the effect of material properties on the performance of braces varies considerably depending on the cross-section geometry.

Optimization‐improved thermal–mechanical simulation of welding residual stresses in welded connections

AbstractThis paper presents a novel computer‐aided computational framework to determine the optimum shape parameters in a welding heat source model using a coupled supervised Gaussian process regression (GPR) and genetic algorithm (GA) approach in estimating the welding residual stresses. The experimental X‐ray diffraction (XRD) approach validates the optimization‐improved thermal–mechanical simulation method. The validation of the proposed approach includes the welded plates with simple geometry to welded pipe‐to‐plate and the circular hollow section joints with complex topologies. The optimization‐derived shape parameters in a welding heat source model lead to close estimates of the temperature history and the welding residual stresses for these types of welded joints considered in this study.