Slender beams are often employed as constituents in engineering materials and structures. Prior experiments on lattices of slender beams have highlighted their complex failure response, where the interplay between buckling and fracture plays a critical role. In this paper, we introduce a novel computational approach for modeling fracture in slender beams subjected to large deformations. We adopt a state-of-the-art geometrically exact Kirchhoff beam formulation to describe the finite deformations of beams in three-dimensions. We develop a discontinuous Galerkin finite element discretization of the beam governing equations, incorporating discontinuities in the position and tangent degrees of freedom at the inter-element boundaries of the finite elements. Before fracture initiation, we enforce compatibility of nodal positions and tangents weakly, via the exchange of variationally-consistent forces and moments at the interfaces between adjacent elements. At the onset of fracture, these forces and moments transition to cohesive laws modeling interface failure. We conduct a series of numerical tests to verify our computational framework against a set of benchmarks and we demonstrate its ability to capture the tensile and bending fracture modes in beams exhibiting large deformations. Finally, we present the validation of our framework against fracture experiments of dry spaghetti rods subjected to sudden relaxation of curvature.

The present study focuses on predicting the behavior of the reinforced concrete (RC) beam–column joints when subjected to seismic loads with the newly proposed concrete damage plasticity (CDP) model for modeling the behavior of concrete. ABAQUS/CAE is used to model the behavior of beam–column joint. Input parameters for the concrete damage plasticity model are adopted from the proposed model. Parametric studies are performed for studying the influence of variation of the dilation angle and eccentricity on the behavior of the beam–column joint when subjected to seismic loads. Ultra High-Performance Fiber Reinforced Concrete (UHPFRC) strip is used for strengthening the beam–column joint against seismic loads. The UHPFRC material is wrapped all along the beam–column joint as a layer for strengthening purposes. Three different thicknesses of UHPFRC strips are used for strengthening the beam–column joint to assess the maximum load-carrying capacity. Results indicated that the proposed CDP model is accurately predicting the behavior of the RC beam–column joint. It is observed that as the thickness of the strip increases, the resistance of the beam–column joint against seismic loads is also increased. It is also observed that the UHPFRC material is more ductile when compared with normal concrete.

Stone matrix asphalt (SMA) is a highly rut-resistant gap-graded asphalt mixture. The inclusion of supplementary materials such as fiber, filler, and polymer-modified bitumen (PMB) makes the layer more expensive to construct. This study examined the rutting and fatigue behavior of SMA mixture by partially replacing virgin aggregates and bitumen with reclaimed asphalt pavement (RAP), thus enhancing sustainability. The study compared the laboratory performance of 20%, 30%, and 40% RAP-added SMA mixtures with that of a conventional SMA mixture. The virgin binders were infused with RAP binder at different proportions and were subjected to rheological testing to evaluate miscibility and performance. The results indicated an improvement in rutting and a decrease in fatigue life, with crumb rubber-modified bitumen (CRMB) offering a higher degree of miscibility than styrene-butadiene-styrene (SBS) PMB when infused with RAP binder. From this study, it can be concluded that in a high-quality SMA surface layer, 20% is the most acceptable amount of RAP content. However, if SMA with CRMB60 binder is used as a binder layer, then 30% of RAP can be used to improve performance.