Image-based techniques have been extensively deployed in the fields of condition assessment and structural mechanics to measure surface effects such as displacements or strains under loading. 3D Digital Image Correlation (3D-DIC) is a technique frequently used to quantify full-field strain measurements. This research uses 3D-DIC to detect interior anomalies of structural components, inferred from the

Microstructure determines the most important factors that influence all aspects of the physical properties of the metal. Machine learning based systems allow us to look at the images to find the features of microstructure images which will be useful for classifying such images. These classification outcomes are the fundamental data for many material scientists. However, handcrafted feature vectors

Fractional Fourier transform (FRFT) can transform data into the space of the fractional order domain, where fractional order can be used to search for the maximum value of fault. Instantaneous spectrum estimation is an important method to analyze non-stationary signals. Through it, the transient characteristics of these signals can be obtained in both time and frequency domain. A new fault diagnosis

The high and slender historical masonry minarets are vulnerable to the static and dynamic loads. Performance analyses of minarets are implemented using three-dimensional numerical models in recent years. However, the complex and inhomogeneous nature of historical structures increases the likelihood of incorrect creation of numerical models. For that reason, it is important to know the experimental

During hot fire rocket engine testing, non-contacting measurements are superior to bonded gauges because they are immune to burning, shaking loose, or damage due to the harsh testing conditions. Additionally, when compared to instruments which register at single points, Digital Image Correlation (DIC) has the added benefit in that it collects full-field displacement and strain maps over the duration

The accuracy of force measurement and prediction is of prime importance in the calibration of a force balance in aerodynamic models. Multi-point calibration has recently been introduced which has proven to be a more accurate prediction technique than the traditional single-point calibration technique. This paper describes the multi-point calibration of a double cone model using tri-axial and uniaxial

Real-time digital image point tracking feedback was used to control a servo-hydraulic load train during the loading of a Glass Fiber Reinforced Plastic (GFRP) cantilever beam. The loading pattern was defined in terms of two translational and one rotational in-plane degrees-of-freedom at a single control point on the beam. Tests were performed with both single-and multi degree-of-freedom controls, using

In this paper, high-density polyethylene (HDPE) composite pipes, reinforced with glass fibers (GF) and carbon nanotubes (CNTs), are manufactured using a novel extruder and multiple molten reprocessing cycles in a screw cylinder barrel. Moreover, the study investigates the tensile strength of the junction of these composite pipes. The results indicate that the Young’s modulus and the ultimate tensile

Acoustoelasticity is an inexpensive and reliable technique for measuring stresses in mechanical structures, provided the influencing factors are controlled. However, ultrasonic waves propagating inside solid bodies are affected by temperature, roughness, differences in microstructure, defects, and others. Non-uniformity is one of the most influential characteristics as it is difficult to evaluate.

To designing various types of components that work in operation under the simultaneous effect of normal stresses, σ, and shear stresses, τ, is important to determine and know the behavior of materials under fatigue compound stress states. A device constructed to introduce into a specimen a state composed of normal and shear stresses is presented herein. The device is intended for performance under

Real-Time Hybrid Substructure (RTHS) testing is a commonly used method to investigate the dynamical influence of a component on a mechanical system. In RTHS, a part of the dynamical system is tested experimentally, while the remaining structure is simulated numerically in a co-simulation. There are several error sources in the RTHS loop that distort the test outcome. To investigate the reliability

Traditional approaches to analyzing nonlinear systems often involve assuming a specific model form and model order for the nonlinearity. These nonlinearities in a system could instead be modeled as a nonlinear force applied to an underlying linear system. Force reconstruction methods can be used to recreate this nonlinear force from measured data, allowing the system change to be quantified. A modal

Railway superstructure components are subject to impact forces caused by irregularities in the rail and wheel or variations in the support stiffness. These imperfections lead to the premature and accelerated deterioration of the track and increase maintenance costs. Generally, to mitigate these dynamic loads, elastomeric rail pads are interposed between rails and sleepers. For each track section, the

The present paper studies the impingement of compressible air jet on a flat plate primarily from the aspect of its application in the domain of pneumatic metrology, i.e. in cases of small distance between the jet nozzle exit and the flat plate. Besides this direct application in the area of pneumatic metrology, the distance between the nozzle exit and the flat plate has been considerably increased

The flatness is a major element for any functional precision surface. It becomes extremely important in the miniaturization of the systems, which require the components of reduced sizes. There is a need to develop appropriate methods to solve measurement problems in industrial design, manufacturing of production and process monitoring. In this work, we used an optical method based on the moiré interferometry

Up to now, similitude methods have been used in order to overcome the typical drawbacks of experimental testing and numerical simulations by reconstructing the full-scale model behavior from that of the scaled model. The novelty of this work is the application of similitude theory not as a tool for predicting the prototype dynamic response, but for supporting, and eventually validating, experimental

The Kolsky Bar, also known as the split-Hopkinson pressure bar, has become one of the most commonly used apparatuses when studying the dynamic behavior of materials. Despite its popularity, limited standards exists with respect to the design, data collection, and data analysis approach used. A lack of standardization can lead to lab-to-lab variation in reported dynamic behavior for nominally identical

Electromagnetic shakers and closed loop control systems are commonly used in qualification tests for environmental vibration conditions. However, shakers have resonances and anti-resonances at high frequencies. Resonances can be beneficial in that the shaker needs to exert less force to achieve the desired environment, but they can make it more challenging for the control system to match the desired

Retrofitting is a technique wherein the damaged structure is strengthened to original design requirements. During 2001 Bhuj earthquake in Gujarat, India many open ground storey building damaged. So there is an urgent need for retrofitting of damaged buildings. This calls for techniques that are technically sound and economically feasible to upgrade deficient and damaged buildings. Also, Portland cement

The hydrodynamic efficiencies of perforated plates arranged at different inclinations are assessed through experimental investigations. Wave absorption capability of the perforated plates is governed by the optimum porosity and the slope of the structure. The reflection and transmission characteristics of waves influenced by the perforated plate exposed to different incident wave conditions are analysed

With the aerospace and aviation industry development, machining deformation is the most prominent and urgent problem in the production process. Studies have shown that initial residual stress (RS) is the main factor causing the deformation of this type of part. Since residual stresses must be analyzed quantitatively, a series of measurement methods have been developed for this purpose. Remarkably,

Blast-induced traumatic brain injury (bTBI) has been widely accepted as a “signature” wound affecting service members in modern conflicts, yet the mechanisms that cause bTBI still remain poorly understood. One of the main reasons for such poor understanding is the technical challenge of reproducing under controlled laboratory conditions the typical time-varying loading cycles induced on brain tissue

The Herbert pendulum, an inverted-pendulum hardness tester, can measure the hardness of various types and shapes of materials from the motion of the pendulum as it swings on a specimen. However, a large experimental system is required to detect the swing angle of the pendulum during the hardness test. This study miniaturized the Herbert hardness system and investigated its accuracy. A new Herbert pendulum

The determination of mechanical and fracture properties of anisotropic tubular materials along hoop direction needs the use of the ring hoop tensile test, for which, the obtained results are deceived by the effect of friction between the ring sample and the D-shaped block mandrel. Commonly, lubricants are applied to reduce the friction, which are inefficient in some specific cases; despite of that

This paper presents experimental, analytical and numerical studies of testing O-rings specimens cut from an St 37 steel pipe. These studies are meant to determine the mechanical properties of the St 37 material and to predict the behavior of its pipes when subjected to internal pressure. This was done by applying transversely concentrated force on relatively small rings (outer diameter = 60.3 mm and

The design of existing tribometers mainly focuses on normal contact and lubricant conditions and aims to evaluate the effect of the load, speed, and environmental conditions on the rubbing pair properties. The effect of the contact angle and variable speed on the rubbing pair properties is often not considered. In this study, a multidirectional adjustment tribometer is developed to evaluate the tribological

Abstract At present, the common method to realize the pre-tightening effect of threaded fasteners is by applying an accurate tightening torque on them. However, when removing the tightening torque, the load characteristics will have a transient conversion, so that the pre-tightening loads will be significantly different from the tightening condition. For the aim of understanding the pre-tightening

In this study, an innovative methodology to experimentally distinguish the ElectroPlastic (EP) effect from the thermal expansion and thermal softening was developed and applied to validate the proposed theoretical electro-mechanical model. Two series of quasi-static uniaxial tension experiments with titanium and copper were conducted and a quadratic dependence was observed of the EP strain on the electric

Cold metal transfer (CMT) welding is a sophisticated version of fusion welding process available with advanced features incorporated in it. During the process of joining metallic parts with CMT, the bead shape and size have significant effects on the weld quality. Typically, bead geometry is characterized by the three important parameters namely weld width, weld depth and reinforcement height. For

To meet users’ needs for the building comfort, this article researched the impact sound insulation performance of timber floor structure under different conditions. The research has been done on a common floor covering and three floating floor coverings (composed of Portuguese cork board, a kind of improved graphite polystyrene sound insulation board (BGL) and expanded polypropylene sound insulation

Temperature has significant effects on modal parameters of a structure. However, it is difficult to do a full-field dynamic measurement and identify modal parameters of the structure under high temperature and working conditions. In this work, three-dimensional digital image correlation combined with Bayesian operational modal analysis is used to yield a full-field non-contact thermal modal testing

Despite tensile testing being commonly used for investigating the mechanical behavior of materials, the occurrence of heterogeneous strain and increasing temperature at high strain rates make the experiment much more complex. This work presents a method integrating synchronous full-field stereo Digital Image Correlation (DIC) and Infrared Thermography (IRT). This method enabled high resolution investigations

A Correction to this paper has been published: https://doi.org/10.1007/s40799-021-00450-8

The acquisition of experimental equipment has become a problem, due to its high costs. To partially solve this problem, the scientific community has used the Arduino data acquisition board (DAB). This board has a low-cost and allows the automation of equipment in a simple and practical way. However, using only the Arduino board is no longer enough, it is now necessary to combine it with the implementation

This study employs time domain reflectometry (TDR) technology for the automatic monitoring of a landslide area to explore rock deformation mechanism in comparison with rock cores and to estimate the location of a potential sliding surface and the amount of the sliding. Comparing to the data from the TDR monitoring and rock cores in Lushan landslide area in Taiwan, sliding surfaces of the landslide

Background: most methods of uncertainty quantification for digital image correlation are orientated towards the research environment and it remains difficult to quantify all of the uncertainty introduced along the measurement chain in an industrial environment. This gap in capability can become critical when physical tests are required for certification purposes. Objective: To develop and demonstrate

Functionally gradient materials (FGM) are new materials that can offer different properties depending on the structure. In this study, two aluminum and copper powders were combined together by the rules of FGM materials. When two different materials are combined in the structure of the FGM, due to the difference in the thermal expansion coefficients of these two materials, residual stresses are created

A Correction to this paper has been published: https://doi.org/10.1007/s40799-021-00442-8

This paper presents a common framework for designing tune mass dampers (TMD) and active mass dampers (AMD) to control the vibrations of shear buildings. This common framework is used for tuning the parameters of TMD and AMD devices in order to achieve a particular control objective. Thus, TMD and AMD can be better compared in practical applications. As an application example, two scaled TMD and AMD

In order to study the rock breaking efficiency of the annular-grooved PDC bit, a test bit with adjustable diameter of 241.3 mm was designed and manufactured. The test bit was used for bench test with adjustable parameters such as width, height, number and radial position of annular groove in two rock samples of sandstone and granite. The results show that compared with conventional PDC bit, the rock-breaking

A Herbert pendulum hardness tester can measure the hardness of a sample with a complex shape, such as a drill bit. Hardness is evaluated based on the free decay curve of the Herbert pendulum in the hardness test. The accuracy of a conventional Herbert hardness test is low because the swing of the pendulum is measured using a level gauge attached to the pendulum. The authors previously proposed a Herbert

The concrete-filled fiber-reinforced polymer tube (CFFT) is a unique structural element that is well suited for reinforced concrete applications in harsh environments due to the corrosion-resistant reinforcement. It also benefits from the stay-in-place formwork capabilities of the reinforcement and the beneficial concrete confinement offered primarily in cases of axial compression. The strength and

Glass laminate aluminum reinforced epoxy (GLARE) is a vital class fiber metal laminates (FMLs) and advanced aircraft material. Despite the ongoing research and utilization of FMLs in applications like structures and aircraft, the weakness is particularly the materials’ delamination. This phenomenon is still observed as the primary confinement for an increased and efficient utilization of the materials

To serve the purpose of their establishment in a beneficial way, dams should be monitored periodically by geodetic or geotechnical methods. To this aim, in this study, geodetic deformation monitoring was conducted on the Deriner Dam, Turkey’s highest double–curvature concrete arc dam. The GNSS measurements were taken within 4 campaigns between the years 2016 and 2017. The geodetic deformation network

Reinforced with steel-cord rubber conveyor belt (SCB), i.e. a unidirectional composite material (CM) with some of the fundamental mechanical properties values of its reinforcement and matrix differing by a factor of ten thousand, is a key infrastructure component of overland minerals transportation industry. Critically, to date no investigative work has been performed on the mechanical behaviour of

Digital image correlation (DIC) is an established test technique in several fields including quasi-static displacement measurements. Recently there has been growing interest in using DIC to measure structural dynamic response and even extract modal parameters from that information. While high-speed cameras have become more ubiquitous, there are no commercial end-to-end packages for modal analysis based

This paper introduces a new test configuration for the determination of panel shear properties in structural sizes. This original test configuration has been successfully applied to calculate the shear properties of beech plywood. A numerical model has been developed to evaluate the influence of such a novel setup in comparison to the common standard. The research includes the mechanical characterization

The passive film mainly consists of oxides and hydroxide and is a key for corrosion protection of metallic materials. It increases the durability and performance of engineering components by spontaneous formation of effective, adherent barrier between the corrosive environment and a substrate. Herein, influence of plastic strain and after heat treatment on austenitic stainless steels was compared with

Classical time-averaging interferometry technique is widely used for MEMS/MOEMS dynamic behavior investigations. It provides useful information on resonant vibration frequencies and mode shapes in the form of Bessel fringe images. To evaluate the information on objects’ vibration amplitude distribution, one needs to further process Bessel fringe images (besselograms). Among different available approaches

In this paper 0.8, 1.2, 1.6 and 2 wt.% of submicron-TiB2 particulate reinforced Al 7075 metal matrix composites (MMCs) were fabricated following a modified liquid metallurgy technique, which included ball milling, semi-solid stirring and ultrasonic agitation assisted squeeze casting method. Objective was to investigate their reinforcement incorporation factors (RIFs), microstructure through optical

Conventionally strain measurements are done in an intrusive way, and, at one or a few discrete points. In this paper, use of a 3D laser measurement system is explored for direct and full-field dynamic strain measurements on compressor and turbine rotor blades. The results are correlated to corresponding FE predictions in a systematic and quantified manner. The ability to measure strain maps on real

In this paper, a method for measuring crack propagation length in the structural fatigue process is presented. A convolutional neural network is presented to eliminate noise interference of matching marks and recognize crack features. The initial region of the crack band is obtained through the convolution neural network result. Based on the initial region, an improved algorithm for tip recognition

The presented six component force balance is a novel design used for many of the force measurements on hydrofoils and other bodies in the University of Tasmania’s cavitation tunnel. This balance is a versatile piece of equipment, the distribution of its six load cells gives it a high degree of sensitivity and stiffness in all directions. The accuracy of the balance in operating conditions has yet to

The friction, wear and mechanical properties of a new non-asbestos brake pad formulation called Premix were investigated. A novel friction-testing machine was utilized to determine tribological behavior. The tribological, physical and mechanical properties of the brake pads were measured and their friction surface morphology was explored via optical and scanning electron microscopy. Results showed

The metal magnetic memory (MMM) method is highly effective in assessing the extent of early damage, such as fatigue crack in ferromagnetic components due to the existence of stress concentration zones (SCZs). However, there are limited studies on the relationship between the magnetic signal parameter in predicting the fatigue life of ferromagnetic components. With the advent of information relating

Reliable and efficient damage detection is critical for the use of lightweight materials in the mechanical and aerospace industries. Within the context of Non-Destructive Testing (NDT), vibration-based tests have been applied for many decades to inspect components without damaging or debilitating their use. For posterior fault recognition, Artificial Intelligence techniques have achieved high success

The conventional triaxial loading in gas seepage studies does not reflect the actual stressing state in the coal seam. Thus, a true triaxial seepage experimental apparatus is developed before seepage tests are conducted with it. The first group of tests is carried out with continuous axial loading under uniform lateral constrain on moulded coal specimen: one test under constant-velocity axial loading

Vortex shedding from an oscillating disc with a chamfered tip is investigated at a Reynolds number of 8715 and a Keulegan–Carpenter number of 0.6. The experiments are performed using a high-speed Particle Image Velocimetry (PIV) system with 160 Hz frame acquisition frequency. Six full cycles are recorded with a total of 1999 recordings, i.e. 333 velocity measurements resolving a single cycle. The 175-mm-diameter

Semi interlocking masonry (SIM) is an innovative masonry building system which is being developed in the Centre for Infrastructure Performance and Reliability at The University of Newcastle, Australia. It utilizes a special method of interlocking of mortar-less engineered masonry panels made of semi-interlocking masonry (SIM) units which possess significant energy dissipation capacity due to friction

This paper deals with a new hybridization methodology of Grey integrated Harmony search algorithm (GR-HSA) for predictive modeling. Simultaneously, parametric optimization during drilling of Graphite reinforced epoxy composites using the TiAlN coated SiC drill. Three process constraints namely spindle speed (N), feed (F), and wt.% of Graphite (G%), varied at four discrete levels, and Taguchi-based