Resumen Estructuras compuestas con capas elásticas y núcleo viscoelástico han sido usadas como tratamiento amortiguador pasivo para reducir las amplitudes de vibraciones. En el proyecto de este tipo de técnica de amortiguación, muchos aspectos deben ser considerados, desde este modelaje computacional hasta ensayos en laboratorio. En este artículo, un abordaje basado en los modelos Golla-Hughes-McTavish (GHM) y Anelastic Displacement Field (ADF) son presentados y aplicados al modelaje de materiales viscoelásticos. Con el fin de evaluar los resultados numéricos se realizó un programa experimental. En este sentido, a partir de las propiedades dinámicas de un material viscoelástico, son evaluados el comportamiento de estructuras sándwich a través de modelos numéricos, enseñándonos las ventajas y desventajas de estas metodologías.

Abstract Composite structures with elastic layers and viscoelastic core have been used as a passive damping treatment applied to reduce vibration amplitudes. In the design phase of this type of damping technique, many aspects ranging from computer modeling to laboratory tests should be considered. Due to the frequency dependency of mechanical properties on these materials, time domain based models for viscoelastic materials are not as numerous as frequency domain based methods. Usually, time domain methods introduce extra dissipation coordinates or internal variables as Golla-Hughes-McTavish (GHM) method and also Anelastic Displacement Field (ADF) method. In this paper, these methods are evaluated by comparing their results to the ones obtained by means of theoretical analysis. Processing time are also evaluated highlighting advantages and disadvantages of these methodologies. Finally, these two-time domain methods are applied to a real structure, pointing out the facilities and difficulties to simulate an actual situation.

Abstract Viscoelastic materials can dissipate a large amount of energy when subjected to cyclic shear deformations, but they have low bearing capacity. Therefore they are often employed as a damping layer in sandwich structures. These sandwich structures present a high damping ratio and simple application. In order to design sandwich structures, many aspects ranging from computer modeling to laboratory testing should be considered. In this study, a test set of experiments were performed and results are compared with a numerical GHM (Golla, Hughes and Mc Tavish method) based model, in order to establish a method to support viscoelastic sandwich beam design. In this way, starting from the dynamic properties of a viscoelastic material, a numerical model is used to evaluate the behavior of these structures. Comparisons with uncontrolled structures are also presented, showing the dissipative characteristics of this passive control.