Investigation into the mechanical behaviour of bio-cemented sands using the discrete element method

Bio-mediated methods, such as microbially induced carbonate precipitation (MICP) and enzyme induced carbonate precipitation (EICP), have gained considerable attention as alternatives to invasive ground improvement techniques. MICP and EICP use biogeochemical processes to drive carbonate precipitation and bind soil grains, thereby improving the...

A Continuously Updated Package-Degradation Model reflecting Thermomechanical Changes at Different Thermo-Oxidative Stages of Moulding Compound

Moulding compounds used for encapsulating electronics typically occupy a large portion of package volume and are most exposed to the external environment. Under harsh conditions such as high temperature, humidity, and mechanical vibrations, constituent materials of electronic components degrade, resulting in a change in their thermal, mechanical...

Shear creep behaviour of soil-structure interfaces under thermal cyclic loading

The coupling effect of initial shear stress and thermal cycles on the thermomechanical behaviour of clay concrete and sand-concrete interfaces has been studied. A set of drained monotonic direct shear tests was conducted at the soil-concrete interface level. Samples were initially sheared to half of the material's shear strength and then they...

On the application of strong thermoplastic–thermoset interactions for developing advanced aerospace-composite joints

In this study, an aerospace thermosetting composite was co-curing joined by Polyether-ether-ketone (PEEK) and Polyethylenimine (PEI) films, with an aim of developing advanced composite joints. The semi-crystalline PEEK films were surface activated upon a UV-irradiation technique to obtain a strong film–composite interface, while the amorphous...

Micromechanics-guided development of strain-hardening alkali-activated composites: Towards a low-carbon built environment

Alkali-activated Materials (AAMs), including those classified as geopolymer, are obtained through the reaction between a solid precursor and an alkaline solution. Compared with ordinary Portland cement (OPC) binders, these materials maintain comparable mechanical properties but have the advantage of reducing greenhouse gas emissions and...

Automatic Psychological Text Analysis using Recurrent Neural Networks

Schema therapy is a type of psychological treatment for people suffering from personality disorders. A schema is a core psychological state of mind that influences external behaviour through the development of coping styles. Current schema therapy is time inefficient and human-processed. Enabling automatic schema classification helps the overall...

Strain hardening behaviour of PVA fibre reinforced geopolymer composites

Strain hardening geopolymer composites (SHGC) as a tailored group of fibre reinforced geopolymer composites are featured by large tensile strain capacity with multiple micro-cracks. This paper experimentally investigates the strain hardening behaviour of SHGC in terms of flexural stress-deflection response, failure mode and cracking, flexural...

Probabilistic strain-fatigue life performance based on stochastic analysis of structural and WAAM-stainless steels

Wire arc additive manufacturing (WAAM) has increasingly attracted attention in the construction sector because of its ability to produce large metallic structural parts in short times. In this paper, Coffin-Manson and Morrow (CMM) equation is employed to compare the fatigue life of WAAM stainless steel with the structural steels S355 and S690...

Spatial-temporal potential exposure risk analytics and urban sustainability impacts related to COVID-19 mitigation: A perspective from car mobility behaviour

Coronavirus disease-2019 (COVID-19) poses a significant threat to the population and urban sustainability worldwide. The surge mitigation is complicated and associates many factors, including the pandemic status, policy, socioeconomics and resident behaviours. Modelling and analytics with spatial-temporal big urban data are required to assist...

On Social Involvement in Mingling Scenarios: Detecting Associates of F-formations in Still Images

In this paper, we carry out an extensive study of social involvement in free standing conversing groups (the so-called F-formations) from static images. By introducing a novel feature representation, we show that the standard features which have been used to represent full membership in an F-formation cannot be applied to the detection of so...

Experimentally validated meso-scale fracture modelling of mortar using output from micromechanical models

This paper presents a validation process of the developed multi-scale modelling scheme on mortar composites. Special attention was paid to make the material structure of real and virtual mortar specimens comparable at the meso-scale. The input mechanical parameters of cement paste (both bulk cement paste and interfacial transition zone) at the...

Discrete lattice fracture modelling of hydrated cement paste under uniaxial compression at micro-scale

A combination of laboratory experiments and numerical simulations at multiple length scales can provide in-depth understanding of fracture behaviour of hydrated cement paste (HCP). To that end, the current work presents a numerical study on compressive failure of hydrated cement paste (HCP) at the micro-scale. Virtual specimens consisting of...

Non-linear bulk micromachined accelerometer for high sensitivity applications

This work describes the design, modelling and realisation of the mechanical part of a non-linear MEMS accelerometer intended for large displacement behaviour. For this, a mass/spring system was designed with an extremely low resonance frequency. In this work the mechanical behaviour was verified by measurements done using an optical setup,...

Thermal inductance in GaN devices

Using the analogue of the electric inductance, we reveal the properties of the thermal inductance in GaN-based light-emitting diode devices by testing their transient thermal behaviors. We find that the devices exhibit a transient thermal response under step-down or step-up currents and observe notable inductive phenomena of the temperature...

Evaluation of a microcapsule based self-healing system for cementitious materials

An international cooperation research project has been financially supported by China Nature Science Foundation, which consists of three relatively independent, but strategically integrated research sub-programs, aiming at the formation of a selfhealing system based on the microcapsule principle for the cementitious composites. In this paper, a...

Evaluation of a microcapsule based self-healing system for cementitious materials

An international cooperation research project has been financially supported by China Nature Science Foundation, which consists of three relatively independent, but strategically integrated research sub-programs, aiming at the formation of a selfhealing system based on the microcapsule principle for the cementitious composites. In this paper, a...