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Presently there exists no way to directly measure strain at high temperatures in engine components such as the combustion chamber, exhaust nozzle, propellant lines, and turbine blades and shaft. The purpose of this paper is to address this issue.

Thermomechanical fatigue (TMF) prediction, which is a critical element for a blade design, is a strong function of the temperature and strain profiles. Major uncertainties arise from the inability of current instrumentation to measure temperature and strain at critical locations. This prevents the structural designer from optimizing the blade design for high temperature environments, which is a significantly challenging problem in engine design.

Being able to directly measure strains in different high temperature zones would deeply enhance the effectiveness of aircraft propulsion systems for fatigue damage assessment and life prediction. The state of the art for harsh environment, high temperature sensors has improved considerably over the past few years.

This paper lays down specifications for high temperature sensors and provides a technological assessment of these new sensing technologies. The paper also reviews recent advances made in harsh environment sensing systems and takes a peek at the future of such technologies.

This paper aims to present the methodology and results of the experimental characterization of three-dimensional (3D) printed acrylonitrile butadiene styrene (ABS) and polycarbonate (PC) parts utilizing digital image correlation (DIC).

Tensile and shear characterizations of ABS and PC 3D-printed parts were performed to determine the extent of anisotropy present in 3D-printed materials. Specimens were printed with varying raster ([+45/−45], [+30/−60], [+15/−75] and [0/90]) and build orientations (flat, on-edge and up-right) to determine the directional properties of the materials. Tensile and Iosipescu shear specimens were printed and loaded in a universal testing machine utilizing two-dimensional (2D) DIC to measure strain. The Poisson’s ratio, Young’s modulus, offset yield strength, tensile strength at yield, elongation at break, tensile stress at break and strain energy density were gathered for each tensile orientation combination. Shear modulus, offset yield strength and shear strength at yield values were collected for each shear combination.

Results indicated that raster and build orientations had negligible effects on the Young’s modulus or Poisson’s ratio in ABS tensile specimens. Shear modulus and shear offset yield strength varied by up to 33 per cent in ABS specimens, signifying that tensile properties are not indicative of shear properties. Raster orientation in the flat build samples reveals anisotropic behavior in PC specimens as the moduli and strengths varied by up to 20 per cent. Similar variations were observed in shear for PC. Changing the build orientation of PC specimens appeared to reveal a similar magnitude of variation in material properties.

This article tests tensile and shear specimens utilizing DIC, which has not been employed previously with 3D-printed specimens. The extensive shear testing conducted in this paper has not been previously attempted, and the results indicate the need for shear testing to understand the 3D-printed material behavior fully.

The purpose of this paper is to focus on the use of a nickel‐titanium (nitinol) shape memory alloy (SMA) wire (capable of showing strains of up to 8 per cent) as the active element that drives a flexible and lightweight micropositioning actuator. The purpose of this paper is to finely control the wire contraction, and as a result, the deflection of the actuator, with micrometric accuracies.

Different experimental platforms are built, all of them using the same nitinol wire as the active element. In all cases a current is applied to the wire to heat it up using the Joule effect, and in doing so cause the wire to transform from the martensite into the austenite. This phase transition has a non‐linear and hysteretic nature, so, finely controling wire's position requires a non trivial control strategy. A neural network used to compensate the hysteretic behaviour of the wire combined with proportional‐integral with antiwindup control strategy is implemented. Control experiments are carried out on a light robot gripper and on a single‐fingered experimental device.

It is found that the single‐fingered device could be used to better analyze the behaviour of the gripper. It is also found that the accuracy obtainable strongly depended on the position sensor used for the feedback, ranging from 3 μm for an linear variable differential transformer sensor to 30 μm for strain gauges mounted on the “fingers” of the grip.

This paper shows the viability of using SMA‐based actuators for lightweight applications, controllable with micrometric accuracies, without the need to place an extraordinarily large burden on the control system.

This paper aims to study both the mechanical properties and the corrosion behavior of the synthesized in situ (TiC-TiB₂) particulates/AZ91 magnesium matrix composite and compare the results with that of the conventional AZ91D alloy.

Scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) were used to study the surface morphology and crystalline structure. Mechanical compression tests were used to investigate the mechanical performance according to ASTM E9-89a. The corrosion behavior of the synthesized magnesium alloy was examined using both electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques in dilute Harrison solutions.

The microstructure of the Mg composite showed a uniform distribution of reinforcing phases. Also, the reinforcing phases were formed without residual intermediate phases. The addition of titanium and boron carbides not only enhanced the mechanical properties of the matrix but also improve its corrosion behavior.

This is the first time that magnesium matrix composite has been to synthesized with TiC and TiB₂ particulates starting from starting from Ti and B carbides powder without adding aluminium using practical and low-cost technique (in situ reactive infiltration technique). This paper studies the corrosion behavior of synthesized Mg matrix in dilute Harrison solution and compares the results with that of conventional AZ91D.

The purpose of this paper was to present how customized implants could be made with specific properties, by setting different values of the laser power, within the selective laser melting (SLM) process. A detailed case study was undertaken and a new multi-structured femoral prosthesis was designed and analyzed, to simulate its behavior for a specific case study.

The materials and manufacturing methods are presented, with details regarding the SLM process, using the Realizer 250 machine. The laser power was varied between 50 and 200 W, thus obtaining samples with different physical and mechanical characteristics. All those sample parts were characterized and their properties were measured.

A practical methodology was found to produce multi-structured implants by SLM. Significant changes of the porosity and properties were found, when modifying the laser power at the SLM machine. The studies have indicated an open porosity varying between 24.810.83 per cent. Tensile tests of the samples showed Young’s modulus values varying between 13.5 and 104.5 GPa and an ultimate stress between 20.2 and 497.5 MPa.

There is no Additive Manufacturing (AM) machine available, to work with different laser power values, in different regions of the same section of the implant. Hence, a multi-structured implant cannot be obtained directly.

The prosthesis should be specifically designed to contain separate models/regions to be made with appropriate laser power values.

This paper presents a new method to design and manufacture a multi-structured implant, using the existing AM equipment. A detailed case study is presented, showing the design procedure, the way to simulate its behavior and the methods to produce the implants by SLM.

The purpose of this paper is to investigate the effect of shock waves and strain hardening effect of laser and shot peening on precipitation‐hardened aluminium alloy AA 6082‐T651.

The hardened layer was evaluated by means of surface integrity with optical microscopy, scanning electron microscope (SEM), energy dispersive spectroscopy, analysis of microhardness and residual stress profiles. Corrosion anodic polarization tests in a 3.5 per cent NaCl water solution were carried out to express a pitting potential and the degree of pitting attack, which was verified on SEM and with 3D metrology.

Research results indicated significant differences between two treatment techniques which had an important influence on the final condition of the surface layer. Potentiodynamic polarization tests inferred that laser peening enabled shift of the pitting potential to more positive values, which ensures higher corrosion resistance.

Results confirmed that the higher corrosion resistance of the laser‐peened specimens against pitting corrosion depends on the modification of the surface, due to ablation during plasma generation. Despite increased surface roughness, laser‐peened specimen exhibits beneficial increase of the pitting/breakdown potential and in reduction of pitting attack degree at the specimen surface.

The purpose of this paper is to describe a new multi‐sensor robotic system designed for riser, mooring lines and umbilical cables in situ underwater inspection. Due to the aggressive operation environment, such structures are susceptible to a broad spectrum of failure causes, such as aging, mechanical, chemical and thermal loads, hydrodynamic stresses, vortex‐induced vibrations and installation or fabrication non‐conformities. Current inspection methods present major risks and inefficiencies, especially as deeper fields are being reached for exploitation.

The SIRIS (In Situ Riser Inspection Robotic System) is designed to reconstruct the actual riser profile and perform non‐destructive tests. The robot is propelled by thrusters to scroll by the outside of the catenary riser. Mechanical, electronic hardware, image acquisition and software/firmware design are described here.

Simulated data from an inertial measurement unit is fused with depth sensor measurements, using a Kalman filter to reconstruct the riser profile, with small localization errors. Laboratory and sheltered waters tests were successfully executed to assess robot subsystems' performance: imaging, leakage, displacement and easiness of operation.

The robot prototype is designed to operate down to 250 m deep, although the final goal is reaching 3,000 m. Tests offshore, in a real oil production platform, have not been performed up to this moment. In the present version, the robot must be coupled to the riser with the aid of a scuba diver.

The robot is expected to allow non‐destructive testing in risers that cannot be performed nowadays with the existing tools. The inspecting procedure is easy to operate and does imply any kind of production stopping. More accurate assessment of the riser structural condition can allow extending its life span, thus avoiding early decommissioning.

Better assessment of actual riser facilities status will have great impact on reducing the chance of oil spill episodes and serious environment damage.

The design, construction and evaluation of a robotic tool for non‐destructive riser inspection has been described. A few similar robots exist in literature but none of them is able to reconstruct the actual riser profile.