Energy-efficient full-range oscillation analysis of parallel-plate electrostatically actuated MEMS resonators

This is the peer reviewed version of the following article: “Fargas Marques, A., Costa Castelló, R. (2017) Energy-efficient full-range oscillation analysis of parallel-plate electrostatically actuated MEMS resonators, 1-13.” which has been published in final form at [doi: 10.1007/s11071-017-3633-8]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."Electrostatic parallel-plate actuators are a common way of actuating microelectromechanical systems, both statically and dynamically. Nevertheless, actuation voltages and oscillations are limited by the nonlinearity of the actuator that leads to the pull-in phenomena. This work presents a new approach to obtain the electrostatic parallel-plate actuation voltage, which allows to freely select the desired frequency and amplitude of oscillation. Harmonic Balance analysis is used to determine the needed actuation voltage and to choose the most energy-efficient actuation frequency. Moreover, a new two-sided actuation approach is presented that allows to actuate the device in all the stable range using the Harmonic Balance Voltage.Peer ReviewedPostprint (author's final draft

Nondestructive monitoring of ageing of Alkali resistant Glass fiber reinforced cement (GRC)

Glass fiber reinforced cement (GRC) is a composite material made of portland cement mortar and alkali resistant (AR) fibers. AR fibers are added to portland cement to give the material additional flexural strength and toughness. However, ageing deteriorates the fibers and as a result the improvement in the mechanical properties resulted from the fiber addition disappears as the structure becomes old. The aim of this paper is monitoring GRC ageing by nondestructive evaluation (NDE) techniques. Two different NDE techniques (1) nonlinear impact resonant acoustic spectroscopy analysis and (2) propagating ultrasonic guided waves are used for this purpose. Both techniques revealed a reduction of the nonlinear behavior in the GRC material with ageing. Specimens are then loaded to failure to obtain their strength and stiffness. Compared to the un-aged specimens, the aged specimens are found to exhibit more linear behavior, have more stiffness but less toughness. Finally, undisturbed fragments on the fracture surface from mechanical tests are inspected under the electron microscope, to understand the fundamental mechanisms that cause the change in the GRC behavior with ageing.The authors want to acknowledge the financial support of the Ministerio de Ciencia e Innovacion MICINN, Spain, and FEDER funding (Ondacem Project: BIA 2010-19933) and BES-2011-044624. Also thanks to PAID-02-11 Program from Universitat Politecnica de Valencia.Eiras Fernández, JN.; Kundu, T.; Bonilla Salvador, MM.; Paya Bernabeu, JJ. (2013). Nondestructive monitoring of ageing of Alkali resistant Glass fiber reinforced cement (GRC). Journal of Nondestructive Evaluation - NDT and E International. 32:300-314. https://doi.org/10.1007/s10921-013-0183-yS30031432Bentur, A., Fibre, M.S.: Reinforced Cementitious Composites, 2nd edn. Taylor and Francis, New York (2007)Purnell, P., Short, N.R., Page, C.L.: A static fatigue model for the durability of glass fibre reinforced cement. J. Mater. Sci. 36(22), 5385–5390 (2001)Ferreira, J.G., Branco, F.A.: Structural application of GRC in telecommunication towers. Constr. Build. Mater. 21(1), 19–28 (2007)Bentur, A., Ben-Bassat, M., Schneider, D.: Durability of glass-fiber-reinforced cements with different alkali-resistant glass fibers. J. Am. Ceram. Soc. 68(4), 203–208 (1985)Cheng, J., Liang, W., Hu, Y., Chen, Q., Frischat, G.H.: Development of a new alkali resistant coating. J. Sol-Gel Sci. Technol. 27(3), 309–313 (2003)Liang, W., Cheng, J., Hu, Y., Luo, H.: Improved properties of GRC composites using commercial E-glass fibers with new coatings. Mater. Res. Bull. 37(4), 641–646 (2002)Payá, J., Bonilla, M., Borrachero, M.V., Monzó, J., Peris-Mora, E., Lalinde, L.F.: Reusing fly ash in glass fibre reinforced cement: a new generation of high-quality GRC composites. Waste Manag. 27(10), 1416–1421 (2007)Zhang, Y., Sun, W., Shang, L., Pan, G.: The effect of high content of fly ash on the properties of glass fiber reinforced cementitious composites. Cem. Concr. Res. 27(12), 1885–1891 (1997)Purnell, P., Short, N., Page, C.: Super-critical carbonation of glass-fibre reinforced cement. Part 1: mechanical testing and chemical analysis. Composites, Part A, Appl. Sci. Manuf. 32(12), 1777–1787 (2001)EN 1170-8:2008. Test method for glass-fibre reinforced cement. Cyclic weathering type testPurnell, P.: Interpretation of climatic temperature variations for accelerated ageing models. J. Mater. Sci. 39(1), 113–118 (2004)Enfedaque, A., Sánchez Paradela, L., Sánchez-Gálvez, V.: An alternative methodology to predict aging effects on the mechanical properties of glass fiber reinforced cements (GRC). Constr. Build. Mater. 27(1), 425–431 (2012)Litherland, K.L., Maguire, P., Proctor, B.A.: A test method for the strength of glass fibres in cement. Int. J. Cem. Compos. Lightweight Concr. 6(1), 39–45 (1984)Itterbeeck, P., Cuypers, H., Orlowsky, J., Wastiels, J.: Evaluation of the strand in cement (SIC) test for GRCs with improved durability. Mater. Struct. 41(6), 1109–1116 (2007)Guyer, R.A., Johnson, P.A.: Nonlinear mesoscopic elasticity: evidence for a new class of materials. Phys. Today 52, 30 (1999)Johnson, P.A.: Nonequilibrium nonlinear dynamics in solids: state of the art. In: Delsanto, P.P. (ed.) Universality of Nonclassical Nonlinearity, pp. 49–69. Springer, New York (2006)Guyer, R.A., McCall, K.R., Boitnott, G.N.: Hysteresis, discrete memory, and nonlinear wave propagation in rock: a new paradigm. Phys. Rev. Lett. 74(17), 3491–3494 (1995)Mayergoyz, I.D.: Mathematical Models of Hysteresis and Their Applications. Academic Press, New York (2003)Van Den Abeele, K.E.A., Carmeliet, J., Ten Cate, J.A., Johnson, P.A.: Nonlinear elastic wave spectroscopy (NEWS) techniques to discern material damage, part II: single-mode nonlinear resonance acoustic spectroscopy. Res. Nondestruct. Eval. 12(1), 31–42 (2000)Chen, J., Jayapalan, A.R., Kim, J.Y., Kurtis, K.E., Jacobs, L.J.: Rapid evaluation of alkali–silica reactivity of aggregates using a nonlinear resonance spectroscopy technique. Cem. Concr. Res. 40(6), 914–923 (2010)Leśnicki, K.J., Kim, J.Y., Kurtis, K.E., Jacobs, L.J.: Characterization of ASR damage in concrete using nonlinear impact resonance acoustic spectroscopy technique. Nondestruct. Test. Eval. Int. 44(8), 721–727 (2011)Bouchaala, F., Payan, C., Garnier, V., Balayssac, J.P.: Carbonation assessment in concrete by nonlinear ultrasound. Cem. Concr. Res. 41(5), 557–559 (2011)Eiras, J.N., Popovics, J.S., Borrachero, M.V., Monzó, J., Payá, J.: Nonlinear impact resonant acoustic spectroscopy to discern mechanical damage in cement based materials. In: 15th International Conference on Experimental Mechanics, Porto, Portugal (2012)Kundu, T.: Ultrasonic Nondestructive Evaluation: Engineering and Biological Material Characterization. CRC Press, Boca Raton (2004)Kundu, T.: Ultrasonic and Electromagnetic NDE for Structure and Material Characterization—Engineering and Biomedical Applications. CRC Press, Boca Raton (2012)Dutta, D., Sohn, H., Harries, K.A., Rizzo, P.: A nonlinear acoustic technique for crack detection in metallic structures. Struct. Health Monit. 8(3), 251–262 (2009)Aymerich, F., Staszewski, W.J.: Impact damage detection in composite laminates using nonlinear acoustics. Composites, Part A, Appl. Sci. Manuf. 41(9), 1084–1092 (2010)EN 1170-1:1998. Precast concrete products. Test method for glass-fibre reinforced cement. Measuring the consistency of the matrix, “Slump test” methodMontgomery, P.L.: A block Lanczos algorithm for finding dependencies over GF(2). In: EUROCRYPT ’95. Lecture Notes in Computer Science, vol. 921, pp. 106–120. Springer, Berlin (1995)EN 1170-5:1998. Precast concrete products. Test method for glass-fibre reinforced cement. Measuring bending strength, “complete bending test” methodRomero, R., Zúnica, L.R.: Métodos Estadísticos en Ingeniería. Universitat Politècnica València, Valencia (2005)Kundu, T.: Fundamentals of Fracture Mechanics. CRC Press, Boca Raton (2008)ASTM C 215:08. Standard Test Method for Fundamental Transverse, Longitudinal, and Torsional Frequencies of Concrete Specimens (2008)Hewlett, P.C.: Lea’s Chemistry of Cement and Concrete, 4th edn. Butterworth-Heinemann, Oxford (2003)Zhu, W., Bartos, P.J.M.: Assessment of interfacial microstructure and bond properties in aged GRC using a novel microindentation method. Cem. Concr. 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Compact model and identification process for friction induced damping in a rotational joint with flawed surfaces

International audienceIt is well known that bolted joints have significant influence on the dynamical behavior of assembled structures due to formation of damping. This paper focuses on damping caused by dry friction in a rotational joint. Friction can be either induced by micro-slipping or macro-slipping. This paper describes the design of a new experimental device intended to measure damping caused by friction and partial slip in rotational joints. An original method for measuring dissipated energy in rotational joints with plan-plan contact is proposed. This method is based on Lagrange formalism and allows to measure accurately forces and torques only with accelerometers. These techniques are available for very small displacements that occur in micro-slip and partial slip of surfaces in contact and are still available for large displacements (macro-slip). An analytical compact model based on the Greenwood model is studied. The experimental results and simulations used to quantify the dissipated energy in order to compute the damping ratio are presented and discussed

Cryptoendolithic growth of the red alga Galdieria sulphuraria in volcanic areas

The habitat of the acido- and thermophilic red algae Galdieria sulphuraria and Cyanidium caldarium was examined in acidic hot sulphur springs in the vicinity of Naples (Italy). These species grew on soil and rocks, but a large part of the populations was cryptoendolithic. The endolithic algal layer (1-3 mm in thickness) was covered by amorphous silica (1-2 mm in thickness) containing traces of hydrotroilite (FeS. nH(2)O) and elemental sulphur. Organotrophic bacteria and fungi were not found in the algal layer. Light penetration measurements showed that 0.1-1% of the sunlight reached the upper part of the algal layer. Thus, low-light-adapted algae should be able to perform some photosynthesis in this endolithic habitat. Under conditions where light is even more limited, e.g. in winter or after darkening of the covering layer, many of the cells might not survive. Aqueous extracts of these algae are excellent growth substrates for Galdieria sulphuraria. Therefore, we propose that compounds released from dead cells in the endolithic layer are used by the surrounding Galdieria cells for heterotrophic metabolism. This would increase their chance of surviving prolonged periods under detrimental conditions

Experimental Study of Bolted Joint Self-Loosening Under Transverse Load

International audienceSelf-loosening of bolted joints is a problem regularly encountered in aeronautical structures and much research has been devoted to this phenomenon. Developing detailed analytical equations for the dynamic study of unscrewing is difficult, so it is easier to reveal it experimentally, in the static or the dynamic case. This paper focuses on the experimental study of the dynamic self-loosening of a bolted joint when it is subjected to vibrations, a major cause of the problem. The experiment used a bolted assembly moved by a shaker, which caused the tightened parts to slide and the bolt to loosen. A load washer showed the axial load variation and a high speed camera recorded the movements of the assembled parts. The results show the progress of rotation of the different parts, the unscrewing of the bolt and the loss of tension in the assembly. The method provides a means to explore the loosening process of various types of bolts, under realistic conditions of vibration