Hysteretic behavior of a belt tensioner: modeling and experimental investigation

In this paper we describe the modeling of the hysteretic behavior of belt tensioners. An initial experimental device is composed only of the tensioner by using forcing frequencies, preloads and deflection amplitudes. It permits the identification of the parameters of the restoring force model used. Comparison of the measured and predicted force deflection loops of the tensioner subjected to large deflections permits preliminary validation of the model.The second experimental device consists of a belt-tensioner system. Its non-linear modeling includes the above hysteretic model and the belt’s longitudinal characteristics. Validation of the belt-tensioner model is completed by comparing the measured and predicted belt tension. Finally, it is shown by using a parametric investigation and phase-plane portrait that the response of the belt-tensioner system increases with the frequency and the amplitude of the excitation

From transmission error measurement to Pulley-Belt slip determination in serpentine belt drives: influence of tensioner and belt characteristics

Serpentine belt drives are often used in front end accessory drive of automotive engine. The accessories resistant torques are getting higher within new technological innovations as stater-alternator, and belt transmissions are always asked for higher capacity. Two kind of tensioners are used to maintain minimum tension that insure power transmission and minimize slip: dry friction or hydraulic tensioners. An experimental device and a specific transmission error measurement method have been used to evaluate the performances of a generic transmission by determining the pulley-belt slip for these two kinds of tensioner. A data acquisition technique using optical encoders and based on the angular sampling method is used with success for the first time on a non synchronous belt transmission. Transmission error between pulleys, pulley/belt slip are deduced from pulley rotation angle measurements.Results obtained show that: the use of tensioner limits belt slip on pulleys, pulley-belt slip is reachable from transmission error measurement, belt non uniform characteristics are responsible of low frequency modulations of transmission error

Rheological and restoring force models regarding belt tensioner dymamic behavior: prediction and experiment

The objective of this paper is to compare the Masing and modified Dahl model efficiency regarding the prediction of the hysteretic behavior of a belt tensioner used for automotive engines. A first experimental study with deflection imposed on the tensioner is carried out to identify hysteresis loop parameters for the two models. The models are then implemented in the general motion equations modeling the behavior of a belt - tensioner - mass system. The comparison beteen numerical and experimental results show that these two models perform satisfactorily and that the modified Dahl model is a little more efficient

An analysis of the modified Dahl and Masing models: application to a belt tensioner

The objective of this paper is to describe the modified Dahl and Masing models used for predicting hysteretic behavior, and tested on a belt tensioner for automotive engines. An experimental study with deflection imposed on the tensioner is first carried out to identify hysteresis loop parameters for the two models. The models are implemented in the general motion equations which govern the behavior of a belt–tensioner–mass system. Particular attention is paid to the use of numerical schemes. The numerical and experimental investigations show the reliability of the modified Dahl model

Experimental investigation on the dynamic characteristics and transverse vibration instabilities of transmission belts

Serpentine belt drives are often used in front end accessory drive of automotive engine. Dynamic characteristics of belts play an important role in the behavior of such transmission and are inputs of simulation software. Moreover, free belt spans exhibit transverse vibration non linear instabilities. An experimental investigation is conducted on multi-ribbed belts, first for the determination of longitudinal stiffness and damping, bending rigidity, then to highlight the belt span transverse instabilities. An experimental set-up has been designed, it enables ,the observation and analysis of instabilities of belt spans axially excited, the determination of instability chart

From transmission error measurement to Pulley-Belt slip determination in serpentine belt drives : influence of tensioner and belt characteristics

Serpentine belt drives are often used in front end accessory drive of automotive engine. The accessories resistant torques are getting higher within new technological innovations as stater-alternator, and belt transmissions are always asked for higher capacity. Two kind of tensioners are used to maintain minimum tension that insure power transmission and minimize slip : dry friction or hydraulic tensioners. An experimental device and a specific transmission error measurement method have been used to evaluate the performances of a generic transmission by determining the pulley–belt slip for these two kinds of tensioner. Transmission error between pulleys, pulley/belt slip are deduced from pulley rotation angle measurements. Results obtained show that : the use of tensioner limits belt slip on pulleys, pulley–belt slip is reachable from transmission error measurement, belt non uniform characteristics are responsible of low frequency modulations of transmission error

Rôle des tendeurs sur le comportement dynamique d’une transmission par courroie

Les transmissions par courroie poly-v (striées), utilisées notamment pour l’entraînement des accessoires d’un moteur automobile, sont généralement équipées d’un galet tendeur afin de réduire les vibrations et de garantir une tension minimum suffisante. Deux types de tendeurs peuvent être utilisés, ils diffèrent par la façon dont est généré l’amortissement : le premier, dit ‘mécanique’ utilise le frottement sec ; le second, dit ‘hydraulique’ est équipé d’un amortisseur. Les deux sont équipés de ressorts de rappel (torsion ou compression). Leur caractérisation expérimentale par des courbes effort–déflection met en évidence des comportements non linéaires différents. L’étude expérimentale d’une transmission pour les 2 types de tendeurs et un tendeur fixe permet d’identifier la contribution de chacun à la dynamique de l’ensemble. La transmission est composée de 4 poulies dont le tendeur reliées par une courroie. Les mesures de vitesses, de vibrations de courroie, de couples et d’effort sont basées sur le principe d’échantillonnage angulaire. Les résultats obtenus montrent que l’utilisation de tendeurs diminue et sature l’amplitude des vibrations longitudinales, décale les zones d’instabilités des vibrations transverses vers des fréquences plus hautes et limite le glissement poulie - courroie

Identification of the non-linear hysteretic behavior of a belt tensioner

Mechanical tensioners are widely used in belt drive systems of automotive engines. They act to maintain a minimum tension in the slack span and to decrease transverse belt vibrations. They are composed of an idler pulley, an arm lever and a torsional springThe paper deals with the modeling of the dynamic behaviour of a tensioner. First an experimental investigation permits the characterisation of the tensioner: it is subjected to a force-deflection test carried out using a specific experimental set-up equipped with an electrodynamic shaker. The hysteretic loops are measured for several deflection amplitudes and forcing frequencies. Then, the experimental characterization permits identifying the parameters required by the original hysteretic model, and classical models like the Dahl’s model. The last part is devoted to the comparison of the hysteretic loops given by the tested models and the experiment

Modélisation de la dynamique vibratoire de train de tiges de forage, comparaison ADAMS/DrillSim

Ce rapport est un Projet de Recherche et Ingénierie mené au sein du laboratoire DrilLab. Il s’intéresseà la dynamique des équipements de forage. Les opérations de forage utilisent une longue structureen rotation introduite à l'intérieur du puits de forage. La dynamique non linéaire avec différentsphénomènes peut provoquer une usure prématurée et des dommages pour les équipements deforage et devraient être étudiés pour améliorer la fiabilité des opérations de forage. Pour ces études,des logiciels de simulation sont employés pour arriver à prévenir ces événements avant qu’ilstiennent lieu. La préconisation de deux de ces logiciels va alors être faite. D’un côté DrillSim, logicieldéveloppé au sein du laboratoire DrilLab qui emploie la méthode des éléments finis et d’un autrecôté Adams Drill, logiciel de MSC Software basé sur la dynamique des multi-corps.<br /

Détermination expérimentale des caractéristiques mécaniques de courroies de transmission

Timing and poly-v belts, used on automotive engine, are flexible links that play an important role and have an accurate design. Their mechanical characteristics influence the dynamic behaviour of the transmissions driven by the belts. Therefore, the measurement of stiffness and damping characteristics of these components is necessary for a better evaluation of their behaviour. Moreover these quantities are input data for belt transmission dynamic behaviour models. Two methods for the determination of the longitudinal stiffness are presented: static/dynamic loading. Bending rigidity has been measured also. All these quantities are determined from the analyses of longitudinal and transverse vibrations of belt span