In the present paper, a dynamic plastic damage model for concrete has been employed to estimate responses of a reinforced concrete slab subjected to blast loading. The interaction between the blast wave and the concre...In the present paper, a dynamic plastic damage model for concrete has been employed to estimate responses of a reinforced concrete slab subjected to blast loading. The interaction between the blast wave and the concrete slab is considered in 3D simulation. In the first stage, the initial detonation and blast wave propagation is modelled in 2D simulation before the blast wave reaches the concrete slab, then the results obtained from 2D calculation are remapped to a 3D model. The calculated blast load is compared with that obtained from TM5-1300. Numerical results of the concrete slab response are compared with the explosive test carried out- in the Weapons System Division, Defence Science and Technology Organisation, Department of Defence, Australia.展开更多
WC based cermet coatings have been considered as alternative replacements to the more traditional hard chrome plating for improved surface properties of aircraft landing gear. While these coatings are used in engineer...WC based cermet coatings have been considered as alternative replacements to the more traditional hard chrome plating for improved surface properties of aircraft landing gear. While these coatings are used in engineering applications requiring superior hardness and improved wear resistance, little is known about the corrosion resistance. In this study, three WC based composite coatings were deposited onto ferritic stainless steel substrates using high velocity oxy fuel (HVOF) technology. Salt spray testing and potentiodynamic scanning studies in a saline environment were conducted on the coatings. Characterisation of the coating structure, composition and morphology, was carried out, prior to and after corrosion testing, using optical microscopy, scanning electron microscopy and EDX elemental analysis. The results showed that poor corrosion performance was exhibited by all three coatings. This was attributed to the high levels of porosity and the presence of micro-cracks within the coatings, resulting in attack of the substrate directly by the saline environment and possible galvanic coupling effects between the substrate and the coating. Dissolution and / or erosion of specific phases within the coating, resulting in the formation of micro-channels and increased number / size of voids may have accelerated corrosion of the system.展开更多
This paper reports on an experimental program of work which investigates the reliability, durability, and packaging of fiber Bragg gratings （FBGs） for application as distributed strain sensors during structural fati...This paper reports on an experimental program of work which investigates the reliability, durability, and packaging of fiber Bragg gratings （FBGs） for application as distributed strain sensors during structural fatigue testing of military platforms. The influence of the FBG fabrication process on sensor reliability is investigated. In addition, methodologies for broad-area packaging and surface-mounting of FBG sensing arrays to defense platforms are developed and tested.展开更多
Epidemics of seasonal influenza inflict a huge burden in temperate climes such as Melbourne(Australia)where there is also significant variability in their timing and magnitude.Particle filters combined with mechanisti...Epidemics of seasonal influenza inflict a huge burden in temperate climes such as Melbourne(Australia)where there is also significant variability in their timing and magnitude.Particle filters combined with mechanistic transmission models for the spread of influenza have emerged as a popular method for forecasting the progression of these epidemics.Despite extensive research it is still unclear what the optimal models are for forecasting influenza,and how one even measures forecast performance.In this paper,we present a likelihood-based method,akin to Bayes factors,for model selection when the aim is to select for predictive skill.Here,“predictive skill”is measured by the probability of the data after the forecasting date,conditional on the data from before the forecasting date.Using this method we choose an optimal model of influenza transmission to forecast the number of laboratory-confirmed cases of influenza in Melbourne in each of the 2010e15 epidemics.The basic transmission model considered has the susceptible-exposed-infectious-recovered structure with extensions allowing for the effects of absolute humidity and inhomogeneous mixing in the population.While neither of the extensions provides a significant improvement in fit to the data they do differ in terms of their predictive skill.Both measurements of absolute humidity and a sinusoidal approximation of those measurements are observed to increase the predictive skill of the forecasts,while allowing for inhomogeneous mixing reduces the skill.We discuss how our work could be integrated into a forecasting system and how the model selection method could be used to evaluate forecasts when comparing to multiple surveillance systems providing disparate views of influenza activity.展开更多
文摘In the present paper, a dynamic plastic damage model for concrete has been employed to estimate responses of a reinforced concrete slab subjected to blast loading. The interaction between the blast wave and the concrete slab is considered in 3D simulation. In the first stage, the initial detonation and blast wave propagation is modelled in 2D simulation before the blast wave reaches the concrete slab, then the results obtained from 2D calculation are remapped to a 3D model. The calculated blast load is compared with that obtained from TM5-1300. Numerical results of the concrete slab response are compared with the explosive test carried out- in the Weapons System Division, Defence Science and Technology Organisation, Department of Defence, Australia.
文摘WC based cermet coatings have been considered as alternative replacements to the more traditional hard chrome plating for improved surface properties of aircraft landing gear. While these coatings are used in engineering applications requiring superior hardness and improved wear resistance, little is known about the corrosion resistance. In this study, three WC based composite coatings were deposited onto ferritic stainless steel substrates using high velocity oxy fuel (HVOF) technology. Salt spray testing and potentiodynamic scanning studies in a saline environment were conducted on the coatings. Characterisation of the coating structure, composition and morphology, was carried out, prior to and after corrosion testing, using optical microscopy, scanning electron microscopy and EDX elemental analysis. The results showed that poor corrosion performance was exhibited by all three coatings. This was attributed to the high levels of porosity and the presence of micro-cracks within the coatings, resulting in attack of the substrate directly by the saline environment and possible galvanic coupling effects between the substrate and the coating. Dissolution and / or erosion of specific phases within the coating, resulting in the formation of micro-channels and increased number / size of voids may have accelerated corrosion of the system.
文摘This paper reports on an experimental program of work which investigates the reliability, durability, and packaging of fiber Bragg gratings （FBGs） for application as distributed strain sensors during structural fatigue testing of military platforms. The influence of the FBG fabrication process on sensor reliability is investigated. In addition, methodologies for broad-area packaging and surface-mounting of FBG sensing arrays to defense platforms are developed and tested.
基金This work was funded by the DSTG project“Bioterrorism Preparedness Strategic Research Initiative 07/301”James M.McCaw is supported by an ARC Future Fellowship(FT110100250)。
文摘Epidemics of seasonal influenza inflict a huge burden in temperate climes such as Melbourne(Australia)where there is also significant variability in their timing and magnitude.Particle filters combined with mechanistic transmission models for the spread of influenza have emerged as a popular method for forecasting the progression of these epidemics.Despite extensive research it is still unclear what the optimal models are for forecasting influenza,and how one even measures forecast performance.In this paper,we present a likelihood-based method,akin to Bayes factors,for model selection when the aim is to select for predictive skill.Here,“predictive skill”is measured by the probability of the data after the forecasting date,conditional on the data from before the forecasting date.Using this method we choose an optimal model of influenza transmission to forecast the number of laboratory-confirmed cases of influenza in Melbourne in each of the 2010e15 epidemics.The basic transmission model considered has the susceptible-exposed-infectious-recovered structure with extensions allowing for the effects of absolute humidity and inhomogeneous mixing in the population.While neither of the extensions provides a significant improvement in fit to the data they do differ in terms of their predictive skill.Both measurements of absolute humidity and a sinusoidal approximation of those measurements are observed to increase the predictive skill of the forecasts,while allowing for inhomogeneous mixing reduces the skill.We discuss how our work could be integrated into a forecasting system and how the model selection method could be used to evaluate forecasts when comparing to multiple surveillance systems providing disparate views of influenza activity.
