Numerical analysis and punching shear fracture based design of longitudinal plate to concrete-filled CHS connections

Prediction of ductile fracture for circular hollow section bracing members under extremely low cycle fatigue

“…Ductile fracture of metals is dependent on stress triaxiality (η) and Lode angle (θ). The MMC model [25], proposed and validated at the material level (coupon) in [25] has been adopted in FE models at member-level by Xu et al [50][51][52]. This fracture model, incorporating a linear damage accumulation rule, has been used to successfully predict ductile fracture initiation and propagation under monotonic loading.…”

“…This fracture model, incorporating a linear damage accumulation rule, has been used to successfully predict ductile fracture initiation and propagation under monotonic loading. In the current study, the MMC model with a nonlinear damage evolution rule [15,53] [50][51]. In addition to the parameters A and n, the material parameter c2 352 accounting for the shear strength, based on the physical implications of the Mohr-Coulomb 353 model, can be estimated from conventional tensile test results [50].…”

Punching Shear Mechanism Based Design of Concrete-Filled CHS T-Joints under In-Plane Bending

“…These limit the further application of MMC criterion in the memberlevel analyses. Therefore, the simplified calibration methodology using general tensile coupon tests was proposed by Xu et al [12] and has been verified and successfully applied to capture the initiation and propagation of punching shear failure in the various memberlevel FE models [12,13,17]. The values of the calibrated MMC parameters in this study are summarized in Table 3.…”

“…The solid element, C3D8R, was used to model the steel tube, weld and inner concrete. Though the convergence problem was not expected to occur, the sensitivity analysis on mesh was also conducted [12,13] to find an appropriate element size with both accurate simulation result and acceptable computational time, since element size would also affect the stable increment of FE model in ABAQUS/Explicit. Therefore, the total number of elements was approximately 50,000 for the concrete part and 29,000 for the steel tubular joint part.…”

“…4. Furthermore, the propriate fixed mass scaling factor (MSF) was assessed [12,13] and the value of 10 6 was employed into the models at beginning to achieve both computational efficiency and the calculation accuracy. The boundary condition was set as the test and the moment load was applied by the tensile force on the end of brace member at a speed of 0.5 mm/min as it in the test.…”