This paper presents results of a series of reverse geometry normal plate impact experiments designed to investigate the onset of incipient plasticity in commercial purity polycrystalline magnesium (99.9%) under weak uniaxial strain shock compression and elevated temperatures up to melt.  Strategic modifications made to the existing single-stage gas-gun facility enable dynamic material behavior characterization under extreme conditions, i.e. ultra-high strain-rates (~10⁶/s) and test temperatures up to 1000 °C.  In this custom configuration, thin metal samples (flyer plate) carried by the specially designed heat-resistant sabot are allowed to be heated uniformly across the diameter in a 100 mTorr vacuum prior to impact by a resistance coil heater with axial and rotational degrees of freedom at the breech end of the gun barrel.  Moreover, a compact fiber-optics-based heterodyne combined normal and transverse displacement interferometer is designed and implemented.  Like the standard PDV, this diagnostic tool is assembled using commercially available telecommunications hardware and uses a 1550 nm wavelength 2W fiber-coupled laser, an optical probe, and single mode fibers to transport light to and from the target.  Using this unique approach, normal plate impact experiments are conducted on preheated (room temperature to near melt point of magnesium) 99.9% polycrystalline magnesium using Inconel 718 target plates at impact velocities ranging from 100 m/s to 110 m/s.  The stress at flyer/target interface, as inferred from the measured normal particle velocity history at the free (rear) surface of the target plate shows progressive weakening with increasing sample temperatures below melt; at higher test temperatures, the rate of softening in stress is observed to weaken and even reverse as the sample temperatures approach the melt point of magnesium samples.  Scanning electron microscopy is utilized to understand the evolution of sample material microstructure following the impact event.

This paper shows an overview of different analyses regarding current challenges at self-pierce riveting with solid rivets as well as semi-tubular rivets of lightweight materials like aluminum die casting, carbon fiber reinforced plastic and 7xxx series aluminum alloy. The joining process analyses will demonstrate the cause and the development as well as the influence on joint quality of individual joining process-induced defects. In addition, methods are described how these imperfections can be avoided or reduced.

To characterize the mechanical behaviour at high temperature close to the melting point, a tensile test machine has been developed through resistive heating by Joule effect. A closed chamber is designed to control the working environment. By the two windows in the chamber, the temperature and displacement fields can be measured directly. For the machine, both temperature and tensile force can be controlled by the proportional-integral-derivative controller. In this paper, the main features of the machine’s design and development will be discussed, with a specific section dedicated to the optimization of the specimens’ shape, which is of utmost importance in the context of Joule heating.

Finite Element Model Updating (FEMU) is an intuitive inverse technique enabling to efficiently characterize plastic material behavior. Although, conclusive proof of concept for this method can be found in literature, a thorough understanding of the key FEMU-ingredients and their impact on the identification of plastic anisotropy is currently missing. In this paper, we aim at minimizing the experimental work associated with yield locus identification of sheet metal via homogeneous biaxial tensile tests. To this end, a biaxial tension apparatus with link mechanism is used to generate a heterogeneous deformation field within a perforated cruciform specimen. The experimentally measured force and displacement field are used in the FEMU procedure to identify an anisotropic yield criterion. The FEMU approach is assessed by comparing the results with experimental data acquired from state-of-the-art stress-controlled biaxial tensile test in the first quadrant of stress-space.

Pathein suspension bridge situated in Pathein city in the south of Myanmar has shown various symptoms of damage and the safety of the bridge is questionable. The authority concerned reported that the bridge is undergoing severe deteriorations since its construction, namely towers’ inclination, excessive deflections, bearing failure, heavy corrosion of main cables and hangers, hangers’ inclination, and slippage of clamps. The deformed shape of the stiffening girder was found to be unusual with maximum deflection nearer to the towers, however, in a single span bridge, such as Pathein bridge, the maximum deflection is expected to be at mid-span. This paper could estimate the possible reasons for the unusual excessive deformations in the stiffening girder and bearing failure. Tension force of hangers was estimated based on vibration measurements, the distribution of hangers’ force was found to be non-uniform with low-tension force in hangers closer to the towers. The non-uniform distribution of the hangers’ tension force is possibly due to shortcomings of the design of the cable system. Towers’ inclination has caused the road level to drop down, however, the unusual deformations in stiffening girder are attributed to the non-uniform distribution of tension force in hangers. Low-tension force in the hangers near towers caused the bearing to carry excessive force, which eventually caused the bearing to fail, the bearing was rehabilitated by adding steel rollers.

A three-dimensional grain mapping technique for polycrystalline materials, called X-ray diffraction contrast tomography (DCT), was developed at SPring-8, which is the brightest synchrotron radiation facility in Japan. The developed technique was applied to an austenitic stainless steel. The shape and location of grains could be determined by DCT using the apparatus in a beam line of SPring-8. To evaluate the dislocation structure in fatigue, the total misorientation of individual grains was measured by DCT. The average value of the total misorientation over one sample was increased with the number of cycles. In a grain, the change of the total misorientation was largest for the primary slip plane. The maximum change of the total misorientation in fatigue was larger for planes with larger Schmid factor, and the first fatigue crack initiation was occurred in a grain, which had the greatest change of the total misorientation.

Experimental data from full-scale experiments with reinforced concrete buildings exposed to blast loading are limited. As full-scale experiments are expensive, numerical simulations of the global response of structures exposed to blast loading may be an attractive substitute. A full-scale experiment on a three-story reinforced concrete building exposed to air-blast is employed to evaluate the performance of FE simulations to represent global response of reinforced concrete structures. The building experienced close to elastic response in the load bearing walls and columns, while cracks were observed in the front wall facing the charge. FE simulations of the global response of the building are performed with a solid element model and a structural element model (shell elements) to compare accuracy to computational cost. The results show that the FE simulations with solid and structural elements give an adequate representation of the global response of the building to a relatively low cost.

The use of a spray application elastomer coating as an effective retrofit strategy for blast and impact mitigation has gained increasing attention in recent years. Despite some encouraging studies in the literature, there remains a great deal yet to be understood, particularly regarding the coating’s impact mitigating capabilities when applied to structural elements. In this work, we consider the application of a spray-on elastomer coating to the impacted face of a concrete cube. High-speed, gas gun experiments are performed on concrete cubes in their uncoated and coated configurations and it is observed that the coating provides a significant protective benefit across the range of test velocities, 45 - 150 m/s. Quasi-static compression and indentation experimental tests are performed on uncoated and coated concrete cubes to inform the development of a numerical model. Despite a number of modelling challenges, we validate our model against experimental measurements and conclude it provides accurate predictions of behaviour at early time steps, before the concrete becomes severely damaged. Future work will focus on using this validated numerical model as an analysis tool for understanding the mechanism by which the elastomer alters the damage response of the underlying concrete substrate.

The inflammation and lipid accumulation in the arterial wall represents a progressive disease known as atherosclerosis. In this study, a numerical model of atherosclerosis progression was developed. The wall shear stress (WSS) and blood analysis data have a big influence on the development of this disease. The real geometry of patients, and the blood analysis data (cholesterol, HDL, LDL, and triglycerides), used in this paper, was obtained within the H2020 SMARTool project. Fluid domain (blood) was modeled using Navier-Stokes equations in conjunction with continuity equation, while the solid domain (arterial wall) was modeled using Darcy’s law. For the purpose of modeling low-density lipoprotein (LDL) and oxygen transport, convection-diffusion equations were used. Kedem-Katchalsky equations were used for coupling fluid and solid dynamics.

We report an easy-to-use Lab-on-Chip (LoC) device able to detect soluble, circulating biomarkers in plasma that are relevant to Coronary Artery Disease (CAD). The LoC prototype is developed within the SMARTool European project and is intended to be used for Point-of-Care (PoC) testing of patients with CAD, facilitating more rapid and efficient monitoring and treatment decisions. It will be part of a broader decision support system for the diagnosis, prognosis and treatment of CAD patients.

A device that enables performing an Enzyme-Linked Immunosorbent Assay (ELISA) on chip was developed and an ELISA protocol for the detection of selected biomarkers was established (Figure 1). The detection chamber of the chip was functionalised with antibodies that are physically adsorbed on the surface of the plastic chip, to selectively capture specific biomarkers in the input sample. The biomarker targeted was human ICAM-1 protein, which is implicated in the role of recruiting inflammatory cells and in combination with lipids and lipoproteins is responsible for atherosclerosis. For the detection of this biomarker, an optical Complementary Metal–Oxide–Semiconductor (CMOS) sensor was integrated on the system that measured the chemiluminescent signal emitted when the ELISA was completed. The parameters and protocol of the assay were optimised and the detectable concentration range was determined.

The previously described system, is controlled using external pumping equipment. Aiming to the creation of a tool that can be used by operators with no specific training in microfluidics, it was important to work towards a system that is autonomous. An integrated flow control system based on capillary flow, was developed in order to be able to minimize the requirements in terms of ancillary apparatus and human-operation. A technology for capillary-action based flow control combined with an electrostatic actuation mechanism are reported here and they are both integrated in low-cost, thermoplastic microfluidic chips (Figure 2). The devices enable sequential flow of liquids, using no external pumping equipment. The integrated capillary burst valves rely on an abrupt increase in the cross-section of a microfluidic channel causing the capillary filling to stop at the transition. In order to burst the valve and actuate the flow, an electrostatic actuation mechanism is integrated. A voltage is applied between two electrodes that are placed before and after the valve, an electrostatic field is created and the meniscus is attracted towards the second electrode. Application of short duration pulses prevents electrochemical processes that occur at the electrodes once the liquid makes contact with the counter electrode.

We presented here a LoC prototype enabling chemiluminescent assays to be performed on chip targeting biomarkers relevant to CAD. In parallel, we reported a robust technology for electrostatically actuated, capillary burst valve for PoC applications, integrated in potentially disposable, thermoplastic devices. The devices were fabricated using easily scalable fabrication techniques and can be used to perform multistep assays on single-use microfluidic devices. They consume little power during operation, making them suitable for use in handheld instruments. This project has received funding from the EU H2020 research and innovation programme under grant agreement No 689068.