Dynamic behaviour of adobe bricks in compression: The role of fibres and water content at various loading rates

This paper presents the results of an experimental research aimed at assessing the material performance of adobe bricks in compression for a wide range of induced strain rates, from statics to high velocity impact. Adobe connotes a traditional masonry whose bricks are made of sundried soil mixtures possibly reinforced with natural fibres and...

Dynamic simulations of traditional masonry materials at different loading rates using an enriched damage delay: Theory and practical applications

Deformation to fracture evolution of a flexible polymer under split Hopkinson pressure bar loading

The deformation-to-fracture evolution of aflexible polymer material under high-strain-rate compressive loadingconducted by a split Hopkinson pressure bar (SHPB) setup was investigated. Representative tests were carriedout at different strain rate levels, followed by the characterization of dynamic damage after each test. Craze andcrack patterns...

Compressive response of multiple-particles-polymer systems at various strain rates

Multiple-particles-polymer systems of a polyurethane elastomeric matrix embedding 25wt.% and 50wt.% 0.5 mm-diameter PMMA particles were investigated using a split Hopkinson pressure bar (SHPB) setup for revealing the dynamic compressive mechanical response. Taking the 25wt.%-particles-polymer system as a reference case, the characteristics of...

An approach to using Weibull stress analysis in design

Current codes and norms allow for structures to be operated in the transition between ductile and brittle behavior. Further, they often treat the Ductile to Brittle Transition Temperature as a constant even though it is well known to depend on a variety of factors, such as loading rate, constraint, and prior cold deformation. This paper roposes...

Dynamic compressive mechanical response of a soft polymer material

The dynamic mechanical behaviour of a soft polymer material (Clear Flex 75) was studied using a split Hopkinson pressure bar (SHPB) apparatus. Mechanical properties have been determined at moderate to high strain rates. Real time deformation and fracture were recorded using a high-speed camera. Fracture micrographs were examined to explore the...

High-strain-rate tensile mechanical response of a polyurethane elastomeric material

The dynamic tensile mechanical response of a soft polymer material (Clear Flex 75) is investigated using a split Hopkinson tension bar (SHTB). Stress-strain relations are derived to reveal the mechanical properties at moderate and high strain rates. These relations appear to be rate dependent. Under static loading, the polymer exhibits an...

Glass interface effect on high-strain-rate tensile response of a soft polyurethane elastomeric polymer material

The glass interface effect on dynamic tensile response of a soft polyurethane elastomeric polymer material has been investigated by subjecting a glass-polymer system of this polymer material matrix embedded a single 3 mm-diameter glass particle to impact loading in a split Hopkinson tension bar (SHTB) setup. The characteristics of the dynamic...

Relating structural loading rate to tensing rate for fracture mechanics specimens

It is vely well-known that fracture toughness depends on loading rate. Higher strain rates can shift the ductile to brittle transition curve to higher temperatures, resulting in a more brittle structure at the same temperature. However, there is little effort to relate the testing rate to the loading rate within the offshore and maritime...

Impact resistance cryogenic bunker fuel tanks

The increasing use of liquefied natural gas (LNG) as bunker fuel in ships, calls for an elaborate study regarding the risks involved. One particular issue is the vulnerability of cryogenic LNG storage tanks with respect to impact loadings, such as ship collisions and dropped objects. This requires an understanding of the impact resistance of the...

A mesoscale modelling perspective of cracking process and fracture energy under high strain rate tension

This paper presents a numerical modelling study on the simulation of the cracking process and fracture energy in concrete under high strain rate. To capture the stress wave effect and the damage evolution at the meso-length scale, both a homogeneous model with a millimetre-resolution mesh and an explicit heterogeneous mesoscale model with random...

Dynamic tensile resistance of concrete - Split hopkinson bar test

The behavior of concrete structures is strongly influenced by the loading rate. Compared to quasi-static loading, on meso and macro-scale concrete loaded by impact loading acts in a different way. First, there is a strain-rate influence on strength, stiffness, ductility, and, second, there are inertia forces activated which influence the...

Polyurethanes for potential use in transparent armour investigated using DSC and DMA

A material combination that may be applied as transparent armour is glass-clad polyurethane. These are comprised of a relatively thin glass strike face and a relatively thick (transparent) polyurethane backing layer. Three transparent polyurethane samples were investigated using differential scanning calorimetry (DSC) and dynamic mechanical...

The Kieffer dough and gluten extensibility rig - An experimental evaluation

Load-extension tests on flour dough are widely used by plant breeders, millers and bakers. The 'Kieffer dough and gluten extensibility rig' is a small-scale version of the Brabender extensograph, in which test pieces of about 0.4 g are extended. With the Kieffer rig, lower strain rates can be applied than in the Brabender extensograph and the...

An effective split of flow and die deformation calculations of aluminium extrusion

The purpose of the research project of which this paper is a result is to gain insight in design and control parameters of aluminium extrusion by FE simulations. This is done by means of a thermal FE code based on an ALE algorithm (Dieka). A short overview is given of the material models as well as the FE methods that are used. It is shown that...

Mechanical Properties of Weakly Segregated Block Copolymers. 3. Influence of Strain Rate and Temperature on Tensile Properties of Poly(styrene-b-butyl methacrylate) Diblock Copolymers with Different Morphologies

Poly(styrene-b-butyl methacrylate) diblock copolymers, PS-6-PBMA, with different morphologies are investigated with respect to the influence of strain rate and temperature on tensile properties. In the first part the mechanical properties of bicontinuous and perforated lamellar structure are compared with other morphologies. Diblock copolymers...

The effect of strain rate on hydrogen distribution in round tensile specimens

Round bars under tensile loading are modelled using coupled diffusion elastic-plastic finite element analyses based on a hydrogen transport model. High strain rates result in low hydrogen concentrations in lattice sites, while low strain rates result in high hydrogen concentrations in lattice sites. This could be an explanation why at slow...

Visual strain: a comparison of monitors and head-mounted displays

New methods to measure information uptake and eye strain have been developed. The speed of information uptake is measured with a reading task that demands quick and accurate eyemovements. Accommodative facility is shown to be a good measure for eye strain. A standard monitor and three types of HMDs were compared on both tasks. The HMDs were (i)...