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Interdigital transducers (IDTs), thanks to their multiple capabilities have the potential of increasing versatility of SHM systems. Migration of the IDT technology in SHM systems and devices is reviewed in this paper. A summary review of different types of IDTs is presented and their salient features are presented in terms of their applicability in the Lamb wave based SHM systems. Comprehensive review is provided concerning the implementation of the IDT capabilities towards the development of SHM systems. Experimental results obtained with prototype IDTs are provided for illustration. Finally, future development directions of the IDTs dedicated to SHM systems are outlined.

In this paper a novel concept of a tunable transducer for generation and sensing of the Lamb waves is presented. The proposed transducer is developed based on a commonly applied Interdigital Transducer (IDT). In the proposed design, further referred to as the Tunable IDT (T-IDT), the conventional comb electrodes with fixed pitch are replaced by a series of densely distributed discrete electrode strips. These electrodes can be easily interconnected in different configurations to match the required wavelength without a need of applying physical changes to the electrode layout. In order to verify the properties of the T-IDT, numerical simulations and experimental tests were performed and their results were compared to the ones obtained for the IDT. The outcomes from both the numerical and experimental analyses proved that the beampatterns generated by the T-IDT are similar to those determined for the conventional transducer. Moreover, the changes in electrode connections lead to the changes of phase-amplitude characteristics.

In this paper a novel concept of the MFC based IDT, Tunable Interdigital Transducer (T-IDT), is presented. The proposed transducer is the extension of the MFC based IDT, where the solid comb electrodes are replaced by series of discrete, stripe electrodes which can be connected independently into the groups and connected to the power source. The span between the centers of the electrodes' groups connected to the same phase are corresponding to the nominal wavelength of the wave excited by the transducer. This makes possible matching to different wavelengths without a need of physical changes of the electrodes’ layout.

In this paper, a multibody approach for leaf springs modelling that may be used for full vehicle simulations is presented. Two different configurations of the leaf spring are investigated. The first one reproduces an actual mounting configuration of a leaf spring suspension in a vehicle, including the shackle. In the second configuration, the shackle is eliminated by mounting the leaf spring on linear bearings that are able to move on a guide rail. This allows for better spring rate evaluation, without the influence of shackle’s length and position. Both configurations were modelled in commercially available software LMS Virtual.Lab Motion and tested experimentally. Results of investigations have proved that developed model correctly reproduces behaviour of the leaf spring for dynamic simulations, with better convergence achieved for configuration without shackle. Initial results for static tests have shown significant error in behaviour of the numerical model and experimental test rig. In order to minimize observed errors, the optimization process of the model parameters was performed in Noesis Optimus by means of single-objective optimization. It was proved that presented approach may be used for proper modelling of the leaf spring behaviour, and this type of models may be effectively used in full vehicle simulations.

Recently, intensive research activity in the application of guided waves (GWs) for structural health monitoring (SHM) has been observed. Interdigital Transducer (IDT) is one of the types of transducers used for generating GWs. The main advantages of such transducers include their ability in generating directional and mode-selective waves. The parameters of IDTs have to be adjusted for the excited wavelength. Some geometric parameters as well as the properties of materials used for manufacturing transducers may be defined using widely known analytical relationships [1]. However, in order to accurately determine the parameters of the IDT, numerous simulations and their experimental verification are required [2]. The paper presents a novel, time efficient approach to the virtual prototyping of complex shaped transducers. The proposed procedure consists of the following four steps: (1) designing a transducer based on analytical relations, (2) approximate numerical simulations of designed transducers with a custom-made, computationally efficient code for screening tests, (3) detailed numerical tests employing the multiphysics Finite Element Method (FEM) for the developed IDT design and (4) experimental tests.

During recent years structural health monitoring (SHM) systems have gained growing attention. Widely applied methods in SHM are methods based on the ultrasonic Lamb waves (LWs) which are also known as plate waves. LWs may be generated and sensed using different types of transducers and their selection is essential for the SHM systems performance. Among transducers used for generation and sensing of such waves, Interdigital Transducers (IDTs) are ones of the most promising types. Their main advantages are: mode selectivity, high excitation strength, wave directivity, small sizes and relatively low cost. In most cases IDTs are made of piezoceramics or piezoelectric polymers what makes them stiff and fragile. Contrary to the piezoceramic transducers, the ones based on piezocomposites (i.e.: macro-fiber composite) are flexible with the comparable efficiency of piezoelectric effects. The MFC transducers are usually optimized as actuators and they are not designed to any specific frequency. It appears, however, that sparse comb-like electrodes used in interdigital transducers create very interesting properties of mode selectivity. In the paper, after the introduction and short discussion about advantages and disadvantages of the IDTs, a novel type of the interdigital transducer, based on elastic macro-fiber composite, is presented. Next, the results of the numerical and experimental tests of the MFC based IDT designed for the A0 mode excitation in a 4mm-thick aluminium plate is presented. In the final part of the paper advantages and disadvantages of the investigated transducer are discussed.

IDTs have the potential of increasing the versatility of SHM systems by their multiple capabilities. Migration of the IDT technology in SHM systems and devices is reviewed in this paper. A summary review of different types of IDTs is presented and their salient features are presented in terms of applicability in the Lamb wave based SHM systems. Comprehensive review is provided concerning the implementation of IDT capabilities towards the development of SHM systems. Experimental results obtained with prototype IDTs are provided for illustration. Finally, future development directions of the IDTs dedicated to SHM systems are outlined.

During recent years, an intensive research activity concerning the application of Lamb waves (LWs) for SHM has been observed. LWs may be generated and sensed using different types of transducers, and their selection is essential for the SHM system's performance. Results of the investigation of three types of transducers based on macro-fiber composite (MFC) are presented in this paper; two types of commercially available MFC actuators are compared with a novel type of custom-designed interdigital transducer also based on the MFC substrate. After a short presentation of the piezoelectric transducer designed for SHM applications, details concerning the proposed interdigital transducer design are provided. Beampatterns of the investigated transducers are first compared using numerical FEM simulations, and next, the numerically obtained beampatterns are verified experimentally using laser vibrometry. In the final part of this paper, advantages and disadvantages of the investigated transducers are discussed. Copyright © 2012 John Wiley & Sons, Ltd.

Presented work is devoted to a design process performed for the interdigital transducer, which is a perspective application for the area of structural health monitoring. In order to obtain the desirable characteristic of the transducer fully coupled numerical analyses were performed in ANSYS Multiphysics software. Utilised finite element models considered both structural dynamics and properties of used piezoelectric material. The process of design improvement was preceded by the sensitivity analysis. In order to search for the best electrode pattern selected geometrical features of the transducer were assumed to vary within allowed ranges. The design parameters, which were taken into account, related to the efficiency of proposed transducer design for the emission of acoustic waves in the monitored structure. The search objectives considered the criteria related to the shape of the beampattern and amplitudes of generated Lamb waves. As a result of the optimization procedure, the simultaneous increase of anti-symmetric mode amplitude and the reduction of undesirable symmetric mode amplitude of generated Lamb waves in the direction perpendicular to the transducer fingers was expected. Another aim of the optimization was to minimize the main lobe width and undesirable contribution of both symmetric and anti-symmetric waves in the parallel direction to the transducer fingers. The response surface method and genetic algorithms were used for fast and effective search through the input design domain.

The paper presents the results of analysis performed to search for feasible design improvements for capacitive micromachined ultrasonic transducer. Carried out search has been aided with the sensitivity analysis and the application of Response Surface Method. The multiphysics approach has been taken into account in elaborated finite element model of one cell of described transducer in order to include significant physical phenomena present in modelled microdevice. The set of twelve input uncertain and design parameters consists of geometric, material and control properties. The amplitude of dynamic membrane deformation of the transducer has been chosen as studied parameter. The objective of performed study has been defined as the task of finding robust design configurations of the transducer, i.e. characterizing maximal value of deformation amplitude with its minimal variation.

This paper presents theoretical background and results of experimental research into fault detection, isolation and restoration (FDIR) system for rotating machineries created in Department of Robotics and Mechatronics, AGH University of Science and Technology in Cracow. The presented FDIR system solution concerns the problem of automatic balancing of rotating systems while in operation. Simulations and experimental results proved that application of the presented solution leads to a reduction in the vibrations caused by imbalance, without hindering service. A mechatronic approach to the design process makes this process more effective.

Modular Self-Reconfigurable robot (MSR) is a system composed of a group, connected together identical modules, resulting structure can carry out specific, even complicated tasks. Such design allows for easy reconfiguration of the robot and its structure in order to continuously adapt it to the current needs or tasks, without the use of additional tools. Currently, the use of MSRs is very limited due to the early stage of technology development. In the future this type of robots will probably be widely used in industry and leisure activities. This paper describes the challenges and opportunities facing the modular robots, an explanation of key terms and the latest designs of artificial cell.

The number of applications of Lamb waves (LWs) based structural health monitoring (SHM) has significantly increased in recent decades. The growth of interest results from several advantages of this diagnostic technique, that is, considerable mode selectivity and directivity that allow for the assessment of the technical condition of a monitored structure. Successful applications of LWs in the field of SHM stimulate continuous improvement of the transducers' design to enable capturing more reliable diagnostic data. The paper introduces a new type of transducer that may be used in the LWs based SHM systems, namely tunable-interdigital transducer (T-IDT) based on macro-fiber composites (MFC). The authors provide a short overview on different types of transducers that may be used in SHM applications, followed by a detailed description of the structure of proposed T-IDT. Finally, the results of numerical and experimental tests carried out employing the proposed transducer are discussed and compared to those obtained with a traditional IDT.

In this paper, three motorcycle models of increasing complexity are introduced. The first, and most simple, can be considered an extension of the model developed by Neil Getz in which the non-holonomic constraints have been removed to take into account the sideslip in tires. Also, this model can be viewed as an extension of the popular bicycle model, widely used in analyzing car dynamics. It has been extended with an additional degree of freedom essential to study motorcycle dynamics: the roll angle. Such a model, simple yet detailed enough, will be used as the basis in the development of a virtual rider. The second model is much more complex than the previous one. It includes the real geometry of the steering system and circular tire profiles which greatly increases the size of the equations. This is a multibody model of a complete rigid motorcycle (i.e. it has no suspensions) consisting of 4 bodies: rear wheel, main frame, fork and front wheel. The last model incorporates the front and rear suspensions together with all the features of its predecessor. It has 13 degrees of freedom, 11 of the mechanical system and 2 of the tire relaxation equations. It will be used as a full model for simulation and rider validation. The models presented in this article have been developed using Maple mathematical software which allows symbolic manipulation of equations. Thus, with this set of models, one can study in depth the phenomena that govern motorcycle dynamics since all the equations are available symbolically.Copyright © 2009 by ASME

This paper presents the research results of the first stage of the Marie Curie Project, MYMOSA (MotorcYcle and MOtorcyclist SAfety). One of the aims of MYMOSA is increasing safety of motorcycle’s rider by better understanding of its road behaviour. It can be achieved by simulations of the motorcycle-rider system during road manoeuvres and pre-/crash scenarios. The process of the motorcycle-rider system development and initial results of the road behaviour simulations are presented. The system is divided into three separate elements: controller, motorcycle and rider’s body models. The co-simulations of motorcycle, rider and controller, are performed to determine the behaviour of the system on the road. Obtained simulation results are compared with results from the system without multibody rider’s model. During further work, kinematic and dynamic properties of the rider’s body parts will be used as inputs for crash simulations with detailed rider’s model to determine positions and severity of injuries caused by crash.Copyright © 2009 by ASME

In recent years an intensive research activity into the application of guided waves (GWs) for structural health monitoring (SHM) can be observed. For instance, Lamb waves (LWs) have shown a great potential in monitoring of thin, planar structures. However, due to the dispersive and multimodal nature of the LWs, their snapshots can consist of many pulses even for an intact structure, which makes damage detection very complex. Moreover, small PZT transducers, most commonly used in SHM systems, act normally as omni-directional wave sources; therefore, dense or sparse transducers networks are required for damage localization. Some of the above-mentioned drawbacks of single PZT emitters and sensors can be overcome using interdigital transducers (IDT) designed to excite and sense a single, selected mode. The mode-tuning is performed by changing the span of finger electrodes to match the wavelength of the excited mode for the selected frequency. An IDT is a directional source, therefore, it generates a wave steered to the direction perpendicular to the electrodes. The width of the excited main lobe can be determined by the length of the electrodes. Since many parameters of the IDTs influence the LWs propagation, techniques for the simulation of the wave excitation and propagation are needed. In the paper, numerical tools for the computer aided design and virtual prototyping of the IDTs are presented. The simulation technique is based on the frequency-dependent transfer function of the structure, and due to its computational efficiency it can be used for fast testing of IDTs’ performance and for preliminary transducer design for further finite element simulations, and prototyping.