The Experts below are selected from a list of 189 Experts worldwide ranked by ideXlab platform
Ran Feng - One of the best experts on this subject based on the ideXlab platform.
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Behaviour of grouted stainless steel tubular X-joints with CHS Chord under axial compression
Thin-walled Structures, 2018Co-Authors: Ran Feng, Yu Chen, Kang He, Liqun FuAbstract:Abstract An experimental investigation was conducted on empty and grouted stainless steel tubular X-joints with circular hollow section (CHS) Chord Member under axial compression. A total of 25 specimens including empty tubular joints, tubular joints with grouted brace Members only, tubular joints with grouted Chord Member only and tubular joints with both grouted brace and Chord Members were tested. The joint strengths, failure modes, axial load-vertical displacement curves, axial load-Chord deformation curves and strain distribution curves of all specimens were reported. The corresponding finite element analysis (FEA) was also performed and calibrated against the test results. Therefore, an extensive parametric study was carried out to evaluate the effects of main influential factors ( β , τ , grouting and grout strength) on the behaviour of grouted stainless steel tubular X-joints with CHS Chord Member under axial compression. It is shown from the comparison that the ultimate strengths of empty and grouted stainless steel tubular X-joints generally increased with the increase of the β and τ values. Furthermore, the ultimate strengths of stainless steel tubular X-joints with both grouted brace and Chord Members generally increased with the increase of the grout strength. Whereas, the grout strength has little influence on the ultimate strengths of stainless steel tubular X-joints with grouted Chord Member only. On the other hand, the joint strengths obtained from the tests and parametric study were compared with the design strengths calculated using the current design rules. It is shown from the comparison that the current design rules are generally unconservative for empty and grouted stainless steel tubular X-joints with CHS Chord Member under axial compression. Therefore, the new design equations were proposed in this study, which were verified to be more accurate.
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Investigation of grouted stainless steel SHS tubular X- and T-joints subjected to axial compression
Engineering Structures, 2017Co-Authors: Yu Chen, Ran Feng, Liqun FuAbstract:Abstract An experimental investigation was conducted on empty and grouted stainless steel square hollow section (SHS) tubular X- and T-joints subjected to axial compression. A total of 24 specimens including empty tubular joints, tubular joints with grouted brace Members only, tubular joints with grouted Chord Member only and tubular joints with both grouted brace and Chord Members were tested. The joint strengths, failure modes, axial load-vertical displacement curves, axial load-Chord deformation curves and strain distribution curves of all specimens were reported. The corresponding finite element analysis (FEA) was also performed and calibrated against the test results. Therefore, an extensive parametric study was carried out to evaluate the effects of main influential factors ( β , τ , grouting and grout strength) on the behaviour of grouted stainless steel SHS tubular X- and T-joints subjected to axial compression. It is shown from the comparison that the ultimate strengths of empty and grouted stainless steel SHS tubular X- and T-joints generally increased with the increase of the β and τ values. The enhancement of joint strengths obtained from grouting both brace and Chord Members is much greater than that obtained from grouting Chord Member only. In addition, the ultimate strengths of stainless steel SHS tubular X- and T-joints with both grouted brace and Chord Members generally increased with the increase of the grout strength. Whereas, the grout strength has little influence on the ultimate strengths of stainless steel SHS tubular X-joints with grouted Chord Member only. On the other hand, the joint strengths obtained from the tests and parametric study were compared with the design strengths calculated using the current design rules. It is shown from the comparison that the current design rules are generally conservative for the design of empty stainless steel SHS tubular X- and T-joints subjected to axial compression, but unconservative for the design of grouted stainless steel SHS tubular X- and T-joints subjected to axial compression. Therefore, the new design equations were proposed in this study, which were verified to be more accurate.
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Flexural behaviour of concrete-filled CHS X-joints with curved Chord under out-of-plane bending
Engineering Structures, 2017Co-Authors: Ran Feng, Yu Chen, Tao ChenAbstract:Abstract This paper presents experimental and numerical investigations on empty and concrete-filled circular hollow section (CHS) X-joints with curved Chord under out-of-plane bending. A total of 16 specimens were fabricated by hot-rolled bending the Chord Members into curvature with three different radii to apply out-of-plane bending to the brace Members, in which 6 specimens were tested with empty curved Chord, 6 specimens were tested with concrete filled in the curved Chord only, and 4 traditional empty and concrete-filled CHS X-joints with straight Chord were also tested for comparison. The typical failure modes, axial load-vertical displacement curves, bending moment-Chord deformation curves, bending moment-rotation curves and strain distribution curves of all specimens are reported. The effects of curvature radius of Chord Member and concrete filled in the Chord Member on the joint strength and behaviour under out-of-plane bending were evaluated. It is shown from the comparison that the ultimate strengths of the CHS X-joints with curvature radius of Chord less than 12d0 under out-of-plane bending are closer to those of the traditional CHS X-joints with straight Chord with the increase of the curvature radius of Chord Member. Whereas, the ultimate strengths of the CHS X-joints with curvature radius of Chord less than 12d0 under out-of-plane bending are generally similar to those of the traditional CHS X-joints with straight Chord. Furthermore, the out-of-plane flexural behaviour of CHS X-joints are improved with the increase of the β ratio. Whereas, filling the concrete in the Chord Member cannot enhance the ultimate strengths of CHS X-joints under out-of-plane bending. The joint strengths obtained from the experimental investigation are compared with the design strengths calculated using the current design rules for traditional CHS X-joints with straight Chord under out-of-plane bending, which were demonstrated to be quite conservative. In addition, the corresponding finite element analysis was also performed and calibrated against the test results. The design equations are proposed based on the test and numerical results for empty and concrete-filled CHS X-joints with curved Chord under out-of-plane bending, which were verified to be more accurate.
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Tests of CHS T-joints with convex Chord under axial compression
Journal of Constructional Steel Research, 2016Co-Authors: Ran Feng, Yu Chen, Chaoyang WangAbstract:Abstract An experimental investigation was conducted on circular hollow section (CHS) T-joints with convex hollow and concrete-filled steel tube (CFST) Chord under axial compression. A total of 16 specimens was fabricated by hot-rolled bending the Chord Members into curvature with three different radii to apply axial compression force to the brace Members, in which 6 specimens were tested with convex hollow Chord, 6 specimens were tested with convex CFST Chord, and 4 traditional CHS T-joints with straight hollow and CFST Chord were also tested for comparison. The joint strengths, failure modes, axial load-vertical displacement curves, axial load-Chord deformation curves and strain distribution curves of all specimens are reported. It is shown from the comparison that the ultimate strengths of the CHS T-joints with convex Chord are generally larger than those of the traditional CHS T-joints with straight Chord. Furthermore, the ultimate strengths of traditional CHS T-joints with straight Chord are significantly enhanced by filling the concrete in the Chord Member only. Whereas, the enhancement of the ultimate strengths of CHS T-joints with convex Chord by filling the concrete in the Chord Member only is quite small.
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Experimental and numerical investigations on steel–concrete–PVC SHS joints under axial compression
Construction and Building Materials, 2016Co-Authors: Yu Chen, Ran Feng, Lele XiongAbstract:Abstract This paper presents the experimental and numerical investigations on steel–concrete–PVC SHS joints under axial compression, in which PVC pipes were used as the inner tube of Chord Member and SHS steel tubes were used as the outer tube of Chord Member. A total of 22 joints with different brace to Chord width ratio ( β ), hollow ratio of Chord ( φ ) and shapes of PVC inner tube of Chord were tested, in which two traditional hollow joints and two grouted joints were tested for comparison. The effects of brace to Chord width ratio ( β ), hollow ratio of Chord ( φ ), grout strength and shapes of PVC inner tube of Chord on the structural behavior of steel–concrete–PVC SHS joints under axial compression were evaluated. Failure load and initial stiffness of traditional joints are remarkably enhanced by grouting the Chord Member along its full length, but the ductility is greatly deteriorated. On the other hand, the failure load and initial stiffness of steel–concrete–PVC SHS joints are improved with the increase of the β ratio. Whereas, the failure loads of steel–concrete–PVC SHS joints are weakened with the increase of the φ ratio. Furthermore, the grout strength has insignificant influence on the failure loads of steel–concrete–PVC SHS joints under axial compression. In addition, the steel–concrete–PVC SHS joints with large φ ratio show good ductility. Chord web deflection is larger than the Chord flange indentation for steel–concrete–PVC SHS joints. For steel–concrete–PVC SHS joints with small φ ratio, the root of brace yielded first, while in the ultimate limit state, Chord Member around the joint intersection region were in the elastic phase. For steel–concrete–PVC SHS joints with large φ ratio, Chord Member around the joint intersection region yielded first, while in the ultimate limit state, the root of brace were fundamentally in the elastic phase. The design equations are proposed based on parametric FE analysis results for steel–concrete–PVC SHS joints under axial compression, which are verified to be more accurate.
Ben Young - One of the best experts on this subject based on the ideXlab platform.
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Theoretical analysis of cold-formed stainless steel tubular joints
Engineering Structures, 2015Co-Authors: Ran Feng, Ben YoungAbstract:A theoretical investigation on cold-formed stainless steel tubular T- and X-joints fabricated from square and rectangular hollow section (SHS and RHS) brace and Chord Members was conducted in this study to develop analytical models. High strength stainless steel (duplex and high strength austenitic) and normal strength stainless steel (AISI 304) specimens were considered in the study. The yield line mechanism analysis which is based on the deformed shape of the axially loaded tubular joints observed from experimental and numerical investigations was performed to estimate the stainless steel tubular joint strengths subjected to Chord face failure. The yield line models considered the weld size, the rounded corners of the Chord Member and the plastic hinges at the Chord webs. In addition, the membrane force in the Chord flange and the strain hardening of the material were also considered in the models. The effect of axial Chord preload on the joint strength has been taken into account for the X-joints. Some existing theoretical models were also used to predict the structural behaviour of cold-formed stainless steel tubular joints subjected to Chord side wall failure. The design rules for cold-formed stainless steel tubular joints failed by Chord face and Chord side wall were derived through a combination of theoretical and empirical analyses. Good agreements were achieved between the joint strengths predicted by the proposed design formulae and the results obtained from the experimental and numerical investigations.
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Behaviour of concrete-filled stainless steel tubular X-joints subjected to compression
Thin-walled Structures, 2009Co-Authors: Ran Feng, Ben YoungAbstract:Experimental investigation of concrete-filled stainless steel tubular X-joints fabricated from square hollow section (SHS) and rectangular hollow section (RHS) brace and Chord Members was conducted. High-strength stainless steel (duplex and high-strength austenitic) and normal-strength stainless steel (AISI 304) specimens filled with nominal concrete cylinder strength of 30 MPa were tested. The concrete was filled in the Chord Member of the test specimens along the full Chord length. A total of 25 X-joint tests was performed that consists of 9 test specimens with brace Members and 16 test specimens with steel bearing plates. The axial compression force was applied to the brace Members, which were welded at right angles to the opposing sides of the continuous Chord Member. Local buckling failure of brace was the main failure mode observed during the tests. Therefore, steel bearing plates were used to simulate the brace Members, which avoid failure of the brace Members. These specimens were failed by Chord face failure and Chord side wall failure as well as crushing of concrete. The test results were compared with the design strengths calculated using the CIDECT design rules for concrete-filled carbon steel tubular structures. It is shown that the design strengths calculated using the existing design equations are quite conservative for the test specimens. It is recommended that the influence of stainless steel tubes on the bearing capacity of concrete-filled stainless steel tubular X-joints should be considered in the design rules.
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Tests of concrete-filled stainless steel tubular T-joints
Journal of Constructional Steel Research, 2008Co-Authors: Ran Feng, Ben YoungAbstract:Abstract This paper describes a test program on a wide range of concrete-filled cold-formed stainless steel tubular T-joints fabricated from square hollow section (SHS) and rectangular hollow section (RHS) brace and Chord Members. A total of 27 tests was performed. The Chord Member of the test specimen was filled with concrete along its full length. Both high strength stainless steel (duplex and high strength austenitic) and normal strength stainless steel (AISI 304) specimens filled with nominal concrete cylinder strength of 30 MPa were tested. The axial compression force was applied to the top end of the brace Member, which was welded to the center of the Chord Member. Local buckling failure of brace Member was the main failure mode observed during the tests. Hence, the axial compression force was then applied by means of a steel bearing plate to avoid failure of brace Member. The failure modes of Chord face failure and Chord side wall failure as well as crushing of the concrete infill were observed. All the tests were performed by supporting the Chord Member of the specimen along its entire length to apply the pure concentrated force without any bending moment. The test results were also compared with design rules for carbon steel tubular structures, which is the only existing design guideline for concrete-filled tubular joints. It is shown that the design strengths predicted by the current design rules are quite conservative for the test specimens. It is also recommended that the contribution of stainless steel tubes should be included in the design rules since it has significant effects on the ultimate bearing capacity of concrete-filled stainless steel tubular T-joints.
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Experimental investigation of cold-formed stainless steel tubular T-joints
Thin-walled Structures, 2008Co-Authors: Ran Feng, Ben YoungAbstract:This paper describes a test program on a wide range of cold-formed stainless steel welded tubular T-joints fabricated from square and rectangular hollow section brace and Chord Members. A total of 22 tests was performed. High strength stainless steel (duplex and high strength austenitic) and normal strength stainless steel (AISI 304) specimens were tested. The tests were performed by supporting the Chord Member of the specimen along its entire length with the pure concentrated force applied to the Chord face by the brace Member. The ratio of brace width to Chord width (β) of the specimens varied from 0.5 to 1.0 so that failure modes of Chord face failure and Chord side wall failure were observed. The test results were compared with the design procedures in the Australian/New Zealand Standard for stainless steel structures, CIDECT and Eurocode design rules for carbon steel structures. It is shown that the design strengths predicted by the current design specifications are conservative for the test specimens calculated using the 0.1%, 0.2%, 0.5% and 1.0% proof stresses as the yield stresses. The 0.2% proof stress is comparatively more reasonable to predict the design strengths of stainless steel welded tubular T-joints for both ultimate limit state and serviceability limit state. In this study, it is shown that the ultimate limit state controls rather than the serviceability limit state for most of the test specimens.
Yu Chen - One of the best experts on this subject based on the ideXlab platform.
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Behaviour of grouted stainless steel tubular X-joints with CHS Chord under axial compression
Thin-walled Structures, 2018Co-Authors: Ran Feng, Yu Chen, Kang He, Liqun FuAbstract:Abstract An experimental investigation was conducted on empty and grouted stainless steel tubular X-joints with circular hollow section (CHS) Chord Member under axial compression. A total of 25 specimens including empty tubular joints, tubular joints with grouted brace Members only, tubular joints with grouted Chord Member only and tubular joints with both grouted brace and Chord Members were tested. The joint strengths, failure modes, axial load-vertical displacement curves, axial load-Chord deformation curves and strain distribution curves of all specimens were reported. The corresponding finite element analysis (FEA) was also performed and calibrated against the test results. Therefore, an extensive parametric study was carried out to evaluate the effects of main influential factors ( β , τ , grouting and grout strength) on the behaviour of grouted stainless steel tubular X-joints with CHS Chord Member under axial compression. It is shown from the comparison that the ultimate strengths of empty and grouted stainless steel tubular X-joints generally increased with the increase of the β and τ values. Furthermore, the ultimate strengths of stainless steel tubular X-joints with both grouted brace and Chord Members generally increased with the increase of the grout strength. Whereas, the grout strength has little influence on the ultimate strengths of stainless steel tubular X-joints with grouted Chord Member only. On the other hand, the joint strengths obtained from the tests and parametric study were compared with the design strengths calculated using the current design rules. It is shown from the comparison that the current design rules are generally unconservative for empty and grouted stainless steel tubular X-joints with CHS Chord Member under axial compression. Therefore, the new design equations were proposed in this study, which were verified to be more accurate.
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Investigation of grouted stainless steel SHS tubular X- and T-joints subjected to axial compression
Engineering Structures, 2017Co-Authors: Yu Chen, Ran Feng, Liqun FuAbstract:Abstract An experimental investigation was conducted on empty and grouted stainless steel square hollow section (SHS) tubular X- and T-joints subjected to axial compression. A total of 24 specimens including empty tubular joints, tubular joints with grouted brace Members only, tubular joints with grouted Chord Member only and tubular joints with both grouted brace and Chord Members were tested. The joint strengths, failure modes, axial load-vertical displacement curves, axial load-Chord deformation curves and strain distribution curves of all specimens were reported. The corresponding finite element analysis (FEA) was also performed and calibrated against the test results. Therefore, an extensive parametric study was carried out to evaluate the effects of main influential factors ( β , τ , grouting and grout strength) on the behaviour of grouted stainless steel SHS tubular X- and T-joints subjected to axial compression. It is shown from the comparison that the ultimate strengths of empty and grouted stainless steel SHS tubular X- and T-joints generally increased with the increase of the β and τ values. The enhancement of joint strengths obtained from grouting both brace and Chord Members is much greater than that obtained from grouting Chord Member only. In addition, the ultimate strengths of stainless steel SHS tubular X- and T-joints with both grouted brace and Chord Members generally increased with the increase of the grout strength. Whereas, the grout strength has little influence on the ultimate strengths of stainless steel SHS tubular X-joints with grouted Chord Member only. On the other hand, the joint strengths obtained from the tests and parametric study were compared with the design strengths calculated using the current design rules. It is shown from the comparison that the current design rules are generally conservative for the design of empty stainless steel SHS tubular X- and T-joints subjected to axial compression, but unconservative for the design of grouted stainless steel SHS tubular X- and T-joints subjected to axial compression. Therefore, the new design equations were proposed in this study, which were verified to be more accurate.
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Flexural behaviour of concrete-filled CHS X-joints with curved Chord under out-of-plane bending
Engineering Structures, 2017Co-Authors: Ran Feng, Yu Chen, Tao ChenAbstract:Abstract This paper presents experimental and numerical investigations on empty and concrete-filled circular hollow section (CHS) X-joints with curved Chord under out-of-plane bending. A total of 16 specimens were fabricated by hot-rolled bending the Chord Members into curvature with three different radii to apply out-of-plane bending to the brace Members, in which 6 specimens were tested with empty curved Chord, 6 specimens were tested with concrete filled in the curved Chord only, and 4 traditional empty and concrete-filled CHS X-joints with straight Chord were also tested for comparison. The typical failure modes, axial load-vertical displacement curves, bending moment-Chord deformation curves, bending moment-rotation curves and strain distribution curves of all specimens are reported. The effects of curvature radius of Chord Member and concrete filled in the Chord Member on the joint strength and behaviour under out-of-plane bending were evaluated. It is shown from the comparison that the ultimate strengths of the CHS X-joints with curvature radius of Chord less than 12d0 under out-of-plane bending are closer to those of the traditional CHS X-joints with straight Chord with the increase of the curvature radius of Chord Member. Whereas, the ultimate strengths of the CHS X-joints with curvature radius of Chord less than 12d0 under out-of-plane bending are generally similar to those of the traditional CHS X-joints with straight Chord. Furthermore, the out-of-plane flexural behaviour of CHS X-joints are improved with the increase of the β ratio. Whereas, filling the concrete in the Chord Member cannot enhance the ultimate strengths of CHS X-joints under out-of-plane bending. The joint strengths obtained from the experimental investigation are compared with the design strengths calculated using the current design rules for traditional CHS X-joints with straight Chord under out-of-plane bending, which were demonstrated to be quite conservative. In addition, the corresponding finite element analysis was also performed and calibrated against the test results. The design equations are proposed based on the test and numerical results for empty and concrete-filled CHS X-joints with curved Chord under out-of-plane bending, which were verified to be more accurate.
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Tests of CHS T-joints with convex Chord under axial compression
Journal of Constructional Steel Research, 2016Co-Authors: Ran Feng, Yu Chen, Chaoyang WangAbstract:Abstract An experimental investigation was conducted on circular hollow section (CHS) T-joints with convex hollow and concrete-filled steel tube (CFST) Chord under axial compression. A total of 16 specimens was fabricated by hot-rolled bending the Chord Members into curvature with three different radii to apply axial compression force to the brace Members, in which 6 specimens were tested with convex hollow Chord, 6 specimens were tested with convex CFST Chord, and 4 traditional CHS T-joints with straight hollow and CFST Chord were also tested for comparison. The joint strengths, failure modes, axial load-vertical displacement curves, axial load-Chord deformation curves and strain distribution curves of all specimens are reported. It is shown from the comparison that the ultimate strengths of the CHS T-joints with convex Chord are generally larger than those of the traditional CHS T-joints with straight Chord. Furthermore, the ultimate strengths of traditional CHS T-joints with straight Chord are significantly enhanced by filling the concrete in the Chord Member only. Whereas, the enhancement of the ultimate strengths of CHS T-joints with convex Chord by filling the concrete in the Chord Member only is quite small.
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Experimental and numerical investigations on steel–concrete–PVC SHS joints under axial compression
Construction and Building Materials, 2016Co-Authors: Yu Chen, Ran Feng, Lele XiongAbstract:Abstract This paper presents the experimental and numerical investigations on steel–concrete–PVC SHS joints under axial compression, in which PVC pipes were used as the inner tube of Chord Member and SHS steel tubes were used as the outer tube of Chord Member. A total of 22 joints with different brace to Chord width ratio ( β ), hollow ratio of Chord ( φ ) and shapes of PVC inner tube of Chord were tested, in which two traditional hollow joints and two grouted joints were tested for comparison. The effects of brace to Chord width ratio ( β ), hollow ratio of Chord ( φ ), grout strength and shapes of PVC inner tube of Chord on the structural behavior of steel–concrete–PVC SHS joints under axial compression were evaluated. Failure load and initial stiffness of traditional joints are remarkably enhanced by grouting the Chord Member along its full length, but the ductility is greatly deteriorated. On the other hand, the failure load and initial stiffness of steel–concrete–PVC SHS joints are improved with the increase of the β ratio. Whereas, the failure loads of steel–concrete–PVC SHS joints are weakened with the increase of the φ ratio. Furthermore, the grout strength has insignificant influence on the failure loads of steel–concrete–PVC SHS joints under axial compression. In addition, the steel–concrete–PVC SHS joints with large φ ratio show good ductility. Chord web deflection is larger than the Chord flange indentation for steel–concrete–PVC SHS joints. For steel–concrete–PVC SHS joints with small φ ratio, the root of brace yielded first, while in the ultimate limit state, Chord Member around the joint intersection region were in the elastic phase. For steel–concrete–PVC SHS joints with large φ ratio, Chord Member around the joint intersection region yielded first, while in the ultimate limit state, the root of brace were fundamentally in the elastic phase. The design equations are proposed based on parametric FE analysis results for steel–concrete–PVC SHS joints under axial compression, which are verified to be more accurate.
Di Wu - One of the best experts on this subject based on the ideXlab platform.
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Application of Recursion Algorithm Method in Design of a Chinese Transmission Tower’s Chord Member
Applied Mechanics and Materials, 2012Co-Authors: Di WuAbstract:Optimization method was designed via selecting a series of self calling functions on the basis of application of recursive algorithm method. An optimization method for unifying section of transmission tower’s Chord Member was testified from the example. The procedure to the feasible combination patterns for unifying section was put forward by recursion. Based on the hypothesis of static determination, the sections of the Members in each pattern were shown, and the optimal design can be obtained by comparing existing patterns. Three different constraint inputs of transmission tower were checked by the recursion algorithm method in this paper. The comparison result shows that the design of unifying section save 123 Kg of steel after optimization under the condition of 5 division pattern of Chord Member. The number of possible combination of unifying section pattern was increased sharply, while the optimal weight of tower is decreased with the division of Chord Member.
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application of recursion algorithm method in design of a chinese transmission tower s Chord Member
Applied Mechanics and Materials, 2012Co-Authors: Di WuAbstract:Optimization method was designed via selecting a series of self calling functions on the basis of application of recursive algorithm method. An optimization method for unifying section of transmission tower’s Chord Member was testified from the example. The procedure to the feasible combination patterns for unifying section was put forward by recursion. Based on the hypothesis of static determination, the sections of the Members in each pattern were shown, and the optimal design can be obtained by comparing existing patterns. Three different constraint inputs of transmission tower were checked by the recursion algorithm method in this paper. The comparison result shows that the design of unifying section save 123 Kg of steel after optimization under the condition of 5 division pattern of Chord Member. The number of possible combination of unifying section pattern was increased sharply, while the optimal weight of tower is decreased with the division of Chord Member.
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unifying section of Chord Member of transmission tower based on recursion method
Applied Mechanics and Materials, 2012Co-Authors: Di Wu, Yan XiongAbstract:A unifying section problem of a double circuit power transmissions tower (DCPT)’s Chord Member was studied in this paper. The collision between the theoretic analysis and practical process in optimization of unifying section was proposed. The bourn of each Chord Member’s broken position was taken into consideration. The concept of dynamic programming was cited, and a procedure to get all the feasible combination patterns for unifying section was put forward by recursion. The object function which is the combination of the decision making and the state in every phase was set up. The object function value of whole structure can be obtained based on the previous decision of every phase. The optimization value in a decision of the weight of the tower’s Chord Member was set up though above object function value in a certain combination. At last, the optimization solution is designed via selecting a series of self calling functions on the basis of recursive idea.
Liqun Fu - One of the best experts on this subject based on the ideXlab platform.
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Behaviour of grouted stainless steel tubular X-joints with CHS Chord under axial compression
Thin-walled Structures, 2018Co-Authors: Ran Feng, Yu Chen, Kang He, Liqun FuAbstract:Abstract An experimental investigation was conducted on empty and grouted stainless steel tubular X-joints with circular hollow section (CHS) Chord Member under axial compression. A total of 25 specimens including empty tubular joints, tubular joints with grouted brace Members only, tubular joints with grouted Chord Member only and tubular joints with both grouted brace and Chord Members were tested. The joint strengths, failure modes, axial load-vertical displacement curves, axial load-Chord deformation curves and strain distribution curves of all specimens were reported. The corresponding finite element analysis (FEA) was also performed and calibrated against the test results. Therefore, an extensive parametric study was carried out to evaluate the effects of main influential factors ( β , τ , grouting and grout strength) on the behaviour of grouted stainless steel tubular X-joints with CHS Chord Member under axial compression. It is shown from the comparison that the ultimate strengths of empty and grouted stainless steel tubular X-joints generally increased with the increase of the β and τ values. Furthermore, the ultimate strengths of stainless steel tubular X-joints with both grouted brace and Chord Members generally increased with the increase of the grout strength. Whereas, the grout strength has little influence on the ultimate strengths of stainless steel tubular X-joints with grouted Chord Member only. On the other hand, the joint strengths obtained from the tests and parametric study were compared with the design strengths calculated using the current design rules. It is shown from the comparison that the current design rules are generally unconservative for empty and grouted stainless steel tubular X-joints with CHS Chord Member under axial compression. Therefore, the new design equations were proposed in this study, which were verified to be more accurate.
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Investigation of grouted stainless steel SHS tubular X- and T-joints subjected to axial compression
Engineering Structures, 2017Co-Authors: Yu Chen, Ran Feng, Liqun FuAbstract:Abstract An experimental investigation was conducted on empty and grouted stainless steel square hollow section (SHS) tubular X- and T-joints subjected to axial compression. A total of 24 specimens including empty tubular joints, tubular joints with grouted brace Members only, tubular joints with grouted Chord Member only and tubular joints with both grouted brace and Chord Members were tested. The joint strengths, failure modes, axial load-vertical displacement curves, axial load-Chord deformation curves and strain distribution curves of all specimens were reported. The corresponding finite element analysis (FEA) was also performed and calibrated against the test results. Therefore, an extensive parametric study was carried out to evaluate the effects of main influential factors ( β , τ , grouting and grout strength) on the behaviour of grouted stainless steel SHS tubular X- and T-joints subjected to axial compression. It is shown from the comparison that the ultimate strengths of empty and grouted stainless steel SHS tubular X- and T-joints generally increased with the increase of the β and τ values. The enhancement of joint strengths obtained from grouting both brace and Chord Members is much greater than that obtained from grouting Chord Member only. In addition, the ultimate strengths of stainless steel SHS tubular X- and T-joints with both grouted brace and Chord Members generally increased with the increase of the grout strength. Whereas, the grout strength has little influence on the ultimate strengths of stainless steel SHS tubular X-joints with grouted Chord Member only. On the other hand, the joint strengths obtained from the tests and parametric study were compared with the design strengths calculated using the current design rules. It is shown from the comparison that the current design rules are generally conservative for the design of empty stainless steel SHS tubular X- and T-joints subjected to axial compression, but unconservative for the design of grouted stainless steel SHS tubular X- and T-joints subjected to axial compression. Therefore, the new design equations were proposed in this study, which were verified to be more accurate.