Traffic signals and information signs play a vivid role in maintaining safe travel by guiding drivers on highways and urban roads. Traffic mast arm structures are susceptible to vibrations induced by wind loads. Fatigue-induced failure is common in these structures. However, it is crucial to ascertain the functionality of signal support structures. This paper lays the foundation for a fully computational

Imposing a boundary condition on a structure can significantly alter its dynamic properties. However, sometimes the specifics of the new boundary conditions are not known. When the effects of a boundary condition are uncertain or there is not enough information, engineers need to excite the complex structure to obtain these modified properties. In order to experimentally obtain the new properties,

Commonly available digital image correlation (DIC) tools are designed to evaluate displacement/deformation fields using well-optimized correlation functions and computational procedures. However, real-time monitoring at high sampling rates or tracking motion at predefined locations from large sequence images can be hardly accomplished due to extreme computational costs. As shown in this paper, a lightweight

This paper presents results of an experimental study that focuses on monitoring changes in dynamic characteristics of a damaged and retrofitted two-story reinforced concrete (RC) building model with poor detailing. In the study, ambient vibration tests are performed via four test setup protocols in order to monitor changes in dynamic characteristics before and after such setups. The four main test

Multi-level stator winding failure investigation on the insulation material for industrial induction motor at its incipient stage can achieve tremendous energy savings, minimize maintenance costs, and enhance the operational life. Early detection has the main advantage of preventing motor failure, which gradually leads to catastrophic or complete shutdown. In this paper, the multi-level stator winding

The conventional digital image correlation (DIC) method is not readily applicable for testing creep and hysteresis in high strain polymeric materials at temperatures above room conditions due to the limited field-of-view of the camera and the difficulty associated with heating the specimen during loading. In this work, the previously developed scanner-based digital correlation (SB-DIC) method for in-plane

Many common techniques for flow measurement, such as Particle Image Velocimetry (PIV) or Ultrasonic Doppler Velocimetry (UDV), rely on the presence of reflectors in the fluid. These methods fail to operate when e.g centrifugal or gravitational acceleration leads to a rarefaction of scatterers in the fluid, as for instance in rapidly rotating experiments. In this article we present two low-cost implementations

A substructure hybrid test is an effective approach to reproduce the seismic behavior of engineering structures. The structure is partitioned into several substructures; those with complex behavior are analyzed experimentally, whereas the others are analyzed numerically, combining the merits of physical experiments and numerical simulations. Previous studies often loaded physical substructures in two

Modal tests using ambient excitations might lead to inaccurate results for bridges with the fundamental natural frequencies greater than 1 Hz. Modal tests using passing vehicles as the excitations are proposed for use in this regard. For effective modal tests using passing vehicles as the excitations to take place on full-scale arch bridges, two matters of science should be clarified, i.e., the effects

In this study, the effect of phase shift under multiaxial excitation on fatigue damage was investigated for the roof components of electrical driven bus. The experiments were performed using a servo-hydraulic controlled multiaxial shaker. Firstly, phase degree and concurrence of servo-hydraulic actuators were calculated and compared for in-phase and out-of-phase loading cases. Following response signals

Due to its superior strength at high temperatures P/T91 steel is often applied in the chemical, petrochemical and fossil-fired power generation industries. The high strength is achieved by a suitable martensitic microstructure after appropriate heat treatment procedure. Welding is the most important process of joining the components in such plants, and the heat-affected zone is often the weakest part

Shake table testing is a very efficient tool in earthquake engineering that may be used to enhance construction methods and the overall safety of structures. Shake tables permit investigation of the dynamic behaviour of civil engineering structures. This paper details the development of a uniaxial shake table that was designed and built with the objective of limiting its cost to a moderate amount,

With the continuous consumption of fossil energy, environmental pollution problems have become increasingly prominent, and clean energy forms, such as wind energy, have become the focus of research in various countries. The main form of wind energy utilization is wind turbines. However, the single wind tunnel experiment method limits the experimental research on wind turbine aerodynamic performance

In Liquid Composite Molding (LCM), a fabric can be formed by highly double curved punch geometries. During the forming step, various types of defects can appear and may have a significant influence on the mechanical properties of the final composite materials. Till now, these defects have not been fully studied and/or understood. The aim of this study was to understand the mechanisms leading to the

Current industry standard environmental verification testing methods typically employ a single shaker to subject a component to a desired environment in one axis at a time, which has been shown to result in over- or under-testing on the various axes and hence a poor representation of the desired environment. This paper explores a new verification testing methodology based on a combination of the Transmission

At present, there are various image registration algorithms under active development for digital image correlation techniques. These techniques include the meshfree-based (MFree-based) digital image correlation. However, there exists very little study in advancing the method for better computational efficiency in engineering measurement applications. Also, a comparative investigation against the more

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