Explicit simulation of bolted endplate composite beam-to-CFST column connections

Abstract

This paper explores the use of an explicit solver available in ABAQUS/Explicit to simulate the behaviour of blind bolted endplate connections between composite beams and concrete-filled steel tubular (CFST) columns. Main aspects of the explicit analysis such as solution technique, blind bolt modelling, choice of element type and contact modelling are discussed and illustrated through the simulation of a large-scale test on the considered joint. The mass scaling option and smooth step amplitude are very effective tools to speed up the explicit simulation. Shell elements can be used in modelling the I-beam due to their computational efficiency and accuracy in capturing local buckling effects. With a proper control of the loading rate, the explicit analysis can provide accurate and efficient predictions of the quasi-static behaviour of the bolted endplate composite connections.

Advanced joint slip model for single-angle bolted connections considering various effects

“…This element could be used for nonlinear analysis including contact behaviors, plasticity, and failure. Also, it is proved to be suitable for FE analysis to provide reliable results for steel connections (Egan et al, 2012; Ghindea et al, 2015; Li et al, 2017; Nguyen and Kim, 2009; Oktavianus et al, 2015; Thai et al, 2017; Thai and Uy, 2015). In order to capture a sufficiently accurate prediction of the joint behavior, a relatively fine mesh of the solid elements is employed in the overlapped length of angles while a coarse mesh is implemented for the free extended length of the angle member, as shown in Figure 3(a).…”

“…Since the bolt load tool is currently not available in the explicit solver, the thermal contraction of the bolt shank has been adopted for the bolt load application. A similar approach has been implemented by several researchers (Egan et al, 2012; Thai et al, 2017; Thai and Uy, 2015).…”

Modeling of progressive damage in concrete using multidimensional virtual internal bond method

“…Equations 10 and 11 signify the material response of MVIB model and is solved by employing explicit type of analysis and using user subroutine material model (VUMAT) available in ABAQUS software 38 . By default, explicit analysis implies dynamic calculation, and so in order to simulate quasi‐static condition through VUMAT in ABAQUS, the mass density needs to be tuned, a technique commonly referred to as mass scaling 41–42 . Mass density ( ρ ) is very important as it decides the stress wave speed and, based on the time of calculation, the extent of stress wave propagation in the solid.…”

“…38 By default, explicit analysis implies dynamic calculation, and so in order to simulate quasi-static condition through VUMAT in ABAQUS, the mass density needs to be tuned, a technique commonly referred to as mass scaling. [41][42] Mass density (ρ) is very important as it decides the stress wave speed and, based on the time of calculation, the extent of stress wave propagation in the solid. Very high value of ρ makes the solid very stiff and impedes the stress wave propagation leading to highly localized deformation in the region of load application.…”

“…The implicit time integration scheme for strain update and stress and tangent modulus tensor calculation is not pursued here as the numerical solution diverges in the strain softening regime especially at locations of high stress concentration (e.g., cracks and notches) due to loss of ellipticity and negative eigenvalues of the tangent stiffness tensor. 3,30,31,[40][41][42][43][44] The steps of the explicit integration scheme for stress calculations are as follows.…”