The filling of thin-walled steel tubes with quartz sand can help to prevent the premature buckling of the steel tube at a low cost. During an impact, the internal stress of the quartz sand-filled steel tube column is subjected to not only axial force but also lateral confining force, resulting in complicated internal stress. A suitable sensor for monitoring the internal stress of such a structu...

The objectives of the thesis work were to study the interaction between embedded piezoceramic transducers and composite structures as well as determine techniques to simplify the Lamb waves analysis. Firstly, this study considered the design of the embedded piezoceramic transducers. Secondly, the effect of the embedded transducer on the composite strength as well as the influence of the mechani...

Ultrasonic transducers play a significant role in generating and receiving the acoustic waves in ultrasonic flowmeters. Depending on the required accuracy, the ultrasonic transducers can be installed either in one pair or more in an ultrasonic flowmeter. The main part of an ultrasonic transducer is its piezoceramic element. In this work, four piezoceramic elements with different diameter to thi...

In this paper, we develop nonlinear constitutive equations and resulting system models quantifying the nonlinear and hysteretic field-displacement relations inherent to piezoceramic elements employed in present nanopositioner designs. We focus specifically on piezoceramic rods utilizing d33 motion and piezoceramic shells driven in d31 regimes, but the modeling framework is sufficiently general ...

The article presents resarches for designing and manufacturing of the ultrasonic motors that uses piezoceramic materials. There are presented specific vibrations modes for the studied piezoceramic plates, vibrations that are used to excite the motor activated element (mobile element). Using the finite element method it is really posssible to predict the usefull vibrations that can makes easier ...

The acoustic characteristics of dense and porous piezoceramic disc hydrophones have been studied by finite element modelling (FEM). The FEM results are validated initially by an analytical model for a simple disc of dense piezoceramic material and then it is extended to a porous piezoceramic disc replicating a foam-reticulated sample. Axisymmetric model was used for dense piezoceramic hydrophon...

Cracks in oil and gas pipelines cause leakage which results in property damage, environmental pollution, and even personal injury or loss of lives. In this paper, an active-sensing approach was conducted to identify the crack damage in pipeline structure using a stress wave propagation approach with piezoceramic transducers. A pipeline segment instrumented with five distributed piezoceramic tra...

This paper presents an improved ultrasonic piezoceramic sandwich transducer, utilised for ultrasonic field in narrow lift stations, wet well, flumes and filter beds. The piezoceramic sandwich transducer powered by a signal generator and it is suitable to generate ultrasound with two piezoceramics and the exponential horn at 35 kHz resonance frequency. From the experiments it can be proved that ...

To improve the modeling accuracy of piezoceramic actuator in the precision positioning system, the Duhem hysteretic model of the piezoceramic actuator was proposed. The paper used the polynomial function to approach the piecewise continuous function and f(v) and g(v) in the Duhem model, adopted recursive least squares algorithm and gradient correction algorithm to identify parameter α , polynom...

The harmonic response and modal shapes of axially-symmetrical piezoceramic cylinders (tubes) polarised through the wall thickness have been predicted by finite element methods and determined experimentally. Analysis of ceramic cylinders has concentrated on the effects of the variation of diameter to thickness (d/t) ratios, and change in cylinder length (l). Investigation has taken into account ...