Reconsidering Museums' Climate and Seasonal Adjustment for Vulnerable Artifacts

The paper provides new experimental evidence for vulnerable artifacts on the dependence of failure strain on the loading rate corresponding to typical environmental loads lasting between hours and months. Animal glue-based ground was chosen for this study as an easily available, hygroscopic and brittle material as well as due to its abundance in collections and its relevance when discussing the risk of mechanical damage to objects. Gesso specimens were tested using dynamic mechanical analysis and tensile testing at different frequencies, under a variety of loading rates and temperatures. The time-temperature superposition principle was used to predict the material response to slow deformations (lasting hours to months) that are otherwise inaccessible on laboratory timescales. The results demonstrate that brittle materials such as animal glue-based grounds do not benefit from longer cycles of applied loads as failure strain is not time-dependent within the investigated timescale. El art & iacute;culo proporciona nueva evidencia experimental sobre la dependencia de fallas de tensi & oacute;n para artefactos vulnerables, con la tension correspondiente al estr & eacute;s causado por fluctuaciones ambientales t & iacute;picas con duraciones entre horas y meses. Para este estudio se eligi & oacute; un gesso a base de cola animal por ser un material f & aacute;cilmente disponible, higrosc & oacute;pico y quebradizo, as & iacute; como por su abundancia en las colecciones y su relevancia a la hora de discutir el riesgo de da & ntilde;o mec & aacute;nico a los objetos. Las pruebas se realizaron en muestras de Gesso mediante an & aacute;lisis mec & aacute;nico din & aacute;mico y pruebas de tracci & oacute;n a diferentes frecuencias, bajo una variedad de velocidades de carga y temperaturas. Se utiliz & oacute; el principio de superposici & oacute;n tiempo-temperatura para predecir la respuesta del material a deformaciones lentas (que duran de horas a meses) que de otro modo ser & iacute;an inaccesibles en escalas de tiempo de laboratorio. Los resultados demuestran que los materiales fr & aacute;giles, como el gesso a base de cola animal, no se benefician de los ciclos largos de cargas aplicadas, ya que la deformaci & oacute;n por falla no dependi & oacute; del tiempo dentro de las escalas investigada en este art & iacute;culo.