Adaptive force-based frame element for regularized softening response

Almeida, João Pacheco de; Das, Sandip; Pinho, Rui

doi:10.1016/j.compstruc.2012.03.018

Cited by 26 publications

(11 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…member displacement) level . In the post‐peak branch, the need to use a regularization length makes it possible to indirectly account for them . This paper shows that models based on distributed plasticity elements and classical beam theory can also be adapted to directly incorporate tension shift effects whilst verifying strictly axial equilibrium, thus significantly strengthening the accuracy of these approaches at the local scale.…”

Section: Introductionmentioning

confidence: 97%

Axially equilibrated displacement‐based beam element for simulating the cyclic inelastic behaviour of RC members

Tarquini

Almeida

Beyer

2017

Earthq Engng Struct Dyn

View full text Add to dashboard Cite

SUMMARYDistributed plasticity beam elements are commonly used to evaluate limit state demands for performancebased analysis of reinforced concrete (RC) structures. Strain limits are often preferred to drift limits because they directly relate to damage and are therefore less dependent on member geometry and boundary conditions. However, predicting accurately strain demands still represents a major simulation challenge. Tension shift effects, which induce a linear curvature profile in the plastic hinge region of RC columns and walls, are one of the main causes for the mismatch between experimental and numerical estimates of local level quantities obtained through force-based formulations. Classical displacement-based approaches are instead suitable to simulate such linear curvature profile. Unfortunately, they verify equilibrium only on an average sense due to the wrong assumption on the axial displacement field, leading to poor deformation and force predictions. This paper presents a displacement-based element in which axial equilibrium is strictly verified along the element length. The assumed transversal displacement field ensures a linear curvature profile, connecting accurately global displacement and local strain demands. The proposed finite element is validated against two sets of quasi-static cyclic tests on RC bridge piers and walls. The results show that curvature and strain profiles for increasing ductility demands are significantly improved when axially equilibrated rather than classical displacement-based or force-based elements are used to model the structural members.

show abstract

Section: Introductionmentioning

confidence: 97%

Axially equilibrated displacement‐based beam element for simulating the cyclic inelastic behaviour of RC members

Tarquini

Almeida

Beyer

2017

Earthq Engng Struct Dyn

View full text Add to dashboard Cite

show abstract

“…Therefore, the use of the by-now familiar cantilever with in-plane tip load analysed in Sections 2 and 3 appeared as an appropriate choice. In order to put in evidence the particular features of the present approach, a comparison between a forcebased EBBT, whose formulation can be found in Almeida et al [29], and the current force-based HOBT, is performed. So as to illustrate the simulation of the flexure-shear interaction, the geometrical configuration should be such that expected shear deformation is observable, but on the other hand it should also be relatively small to allow for a meaningful comparison between the two beam theories.…”

Section: Tablementioning

confidence: 99%

Force-based higher-order beam element with flexural-shear-torsional interaction in 3D frames. Part II: Applications

Almeida

Correia

Pinho

2015

Engineering Structures

View full text Add to dashboard Cite

a b s t r a c tThe specific features of the proposed force-based formulation derived in the companion paper, which is applied for the first time to higher-order beam theories, are herein thoroughly validated. Introductory numerical examples illustrate the influence of mesh refinement, boundary conditions, and slenderness ratios for isotropic linear elastic response. Specific higher-order effects-unique to the developed element-are then suitably interpreted, as well as the formulation appropriateness to consider distributed loads and to model three-dimensional behaviour, which is verified with solid finite element analyses. Extensive comparisons against existing proposals, namely other refined higher-order beam theories, emphasize the performance of the proposed approach. Finally, the nonlinear response of the element with a multiaxial J2 linear plasticity material model is analysed, highlighting its advantages in relation to a classical force-based Euler-Bernoulli beam using a one-dimensional plastic material model with kinematic hardening.

show abstract

“…Residual strength and strain: Upon the onset of lap splice degradation, the strength of most test units with lap splices dropped sharply whereas for two test units the loss of strength was more gradual (TW3 and VK2). Postpeak response modelling is a delicate task as it requires challenging procedures to match numerical and physical localization issues (Almeida et al 2012(Almeida et al , 2016Calabrese et al 2010). This applies in particular to brittle deformation mechanisms such as lap splices, which are often characterized by steep softening slopes.…”

Section: Factors Affecting Lap Splice Strength and Strain At Degradatmentioning

confidence: 99%

Influence of Lap Splices on the Deformation Capacity of RC Walls. I: Database Assembly, Recent Experimental Data, and Findings for Model Development

et al. 2017

View full text Add to dashboard Cite

Recent postearthquake missions have shown that reinforced concrete (RC) wall buildings can experience critical damage owing to lap splices, which led to a recent surge in experimental tests of walls with such constructional details. Most of the 16 wall tests described in the literature thus far were carried out in the last six years. This paper presents a database with these wall tests, including the description of a new test on a wall with lap splices and a corresponding reference wall with continuous reinforcement. They complement the existing tests by investigating a spliced member with a shear span ratio smaller than two, which is the smallest among them. The objective of this database is to collect information not just on the force capacity but mainly on the deformation capacity of lap splices in reinforced concrete walls. It is shown that (1) well-confined lap splices relocate the plastic hinge above the lap splice, (2) lap splices with adequate lengths but insufficiently confined attain the peak force but their deformation capacity is significantly reduced, and (3) short and not well-confined lap splices fail before reaching the strength capacity. The analysis of the test results, which are used in the companion paper for the finite element analysis of walls with lap splices, indicates in particular that the confining reinforcement ratio and the ratio of shear span to lap splice length influence the lap splice strain capacity.

show abstract

Adaptive force-based frame element for regularized softening response

Cited by 26 publications

References 41 publications

Axially equilibrated displacement‐based beam element for simulating the cyclic inelastic behaviour of RC members

Axially equilibrated displacement‐based beam element for simulating the cyclic inelastic behaviour of RC members

Force-based higher-order beam element with flexural-shear-torsional interaction in 3D frames. Part II: Applications

Influence of Lap Splices on the Deformation Capacity of RC Walls. I: Database Assembly, Recent Experimental Data, and Findings for Model Development

Contact Info

Product

Resources

About