1,721,986 research outputs found
FLEXURAL CAPACITY OF LONG-SPAN TRANSVERSELY LOADED HOLLOW BLOCK MASONRY WALLS
No full textAn experimental programme was carried out on long-span masonry walls made of hollow concrete blocks. Both low-rise unreinforced walls and tall reinforced walls were subjected to four-point bending tests. The tests aim at obtaining indications on the flexural capacity of partially grouted, long-span masonry walls, which basically consist of unreinforced walls laterally supported by reinforced columns, and are mainly subjected to transverse loads. The tests on reinforced walls were also intended to compare the effectiveness of two types of reinforcement (a traditional one and an innovative one in which stirrups are replaced by metal strips welded to the longitudinal rebars) on the flexural capacity. Eurocode 6 is found to strongly underestimate the experimental flexural strength of the unreinforced walls. The traditional reinforcement was found to be more effective than the innovative one. Eventually, a finite element model of the reinforced walls was developed to try and capture their failure modes. Upon a careful calibration, the numerical model is able to match the experimental ultimate load, although the real transverse displacements cannot be correctly captured
Hierarchical Infills for Additive Manufacturing Through a Multiscale Approach
No full textA numerical method is presented to generate hierarchical infills for additive manufacturing, using homogenization and optimization. Given the shape and the allowed stages of grading, the macroscopic properties of each level of the hierarchical infill are computed through numerical homogenization. Then, a multi-material optimization problem is formulated to find the distribution of the prescribed discrete set of candidates that maximizes the structural stiffness of the object to be printed for a limited volume fraction. The formulation is endowed with an additional overturning constraint to achieve objects that resist gravity in a stable configuration. Numerical simulations, addressing the design of a self-supporting orthotropic rhombic infill and a stiff isotropic triangular one, are shown
A non-rotating anisotropic damage model for brittle materials
No full textE. Onate and D.R.J. Owen Eds
A theoretical model for the description of static and creep-induced damage in brittle materials under non proportional loading.
No full textE. Onate and D.R.J. Owen Eds
Flemish bond brickwork: Macroscopic elastic properties and nonlinear behaviour
No full textAssuming Flemish bond brickwork to be periodic, a finite element model of a Representative Volume Element (RVE) is developed to predict its macroscopic behavior using a homogenization approach. In linear elasticity, the numerical results are used to assess the reliability of recently proposed closed-form expressions for the macroscopic elastic properties (Taliercio, 2018). Assuming that both mortar and units experience plastic strains and damage effects, the macroscopic strength domain under in-plane principal stresses parallel to the joints is identified and compared with that predicted by Drougkas et al. (2016). Eventually, the model is applied to predict the homogenized strength of Flemish bond brickwork under elementary macroscopic in-plane stresses and transverse shear. The effect of the collar joint on the macroscopic response is pointed out by comparing the numerical results with those obtained on header bond brickwork. This effect is shown to be particularly significant under horizontal, transverse shear
Analysis of linear elastic masonry-like solids subjected to settlements
No full textA linear elastic no-tension material model is implemented in this contribution to cope with
the analysis of masonry-like solids in case of either elastic or inelastic settlements. Instead of implementing
an incremental non-linear approach, an energy-based method is adopted to address the
elastic no-tension equilibrium. Under a prescribed set of compatible loads, and possible enforced displacements,
a solution is found by distributing an equivalent orthotropic material having negligible
stiffness in tension, such that the overall strain energy is minimized and the stress tensor is negative
semi-definite all over the domain. A preliminary implementation of the proposed method is given
by adopting a heuristic approach to turn the multi-constrained minimization problem into an unconstrained
one. Numerical simulations focus on a wall with an opening subjected to either inelastic
settlement or standing on elastic soil
- …
