Print Email Facebook Twitter Towards understanding the influence of porosity on mechanical and fracture behaviour of quasi-brittle materials Title Towards understanding the influence of porosity on mechanical and fracture behaviour of quasi-brittle materials: Experiments and modelling Author Liu, D (University of Bristol; University of Oxford) Šavija, B. (TU Delft Materials and Environment) Smith, G.E. (University of Bristol) Flewitt, P.E.J. (University of Bristol) Lowe, T. Schlangen, E. (TU Delft Materials and Environment) Date 2017 Abstract In this work, porosity-property relationships of quasi-brittle materials are explored through a combined experimental and numerical approach. In the experimental part, hemihyrate gypsum plaster powder (CaSO 4 ⋅1/2H 2 O CaSO4⋅1/2H2O) and expanded spherical polystyrene beads (1.5–2.0 mm dia.) have been mixed to form a model material with controlled additions of porosity. The expanded polystyrene beads represent pores within the bulk due to their light weight and low strength compared with plaster. Varying the addition of infill allows the production of a material with different percentages of porosity: 0, 10, 20, 30 and 31 vol%. The size and location of these pores have been characterised by 3D X-ray computed tomography. Beams of the size of 20×20×150 20×20×150 mm were cast and loaded under four-point bending to obtain the mechanical characteristics of each porosity level. The elastic modulus and flexural strength are found to decrease with increased porosity. Fractography studies have been undertaken to identify the role of the pores on the fracture path. Based on the known porosity, a 3D model of each microstructure has been built and the deformation and fracture was computed using a lattice-based multi-scale finite element model. This model predicted similar trends as the experimental results and was able to quantify the fractured sites. The results from this model material experimental data and the lattice model predictions are discussed with respect to the role of porosity on the deformation and fracture of quasi-brittle materials. Subject Quasi-brittle materialsPorosityStrengthMicrostructure To reference this document use: http://resolver.tudelft.nl/uuid:93ac17ab-a727-4f0f-be49-6ee1c40ee168 DOI https://doi.org/10.1007/s10704-017-0181-7 ISSN 0376-9429 Source International Journal of Fracture, 205, 57-72 Part of collection Institutional Repository Document type journal article Rights © 2017 D Liu, B. Šavija, G.E. Smith, P.E.J. Flewitt, T. Lowe, E. Schlangen Files PDF art_3A10.1007_2Fs10704_01 ... 0181_7.pdf 3.52 MB Close viewer /islandora/object/uuid:93ac17ab-a727-4f0f-be49-6ee1c40ee168/datastream/OBJ/view