New non-destructive testing techniques based on mechanical waves: Development and application to damage characterization on non-homogeneus materials
This doctoral thesis is developed in materials, Non-Destructive Testing (NDT) and signal processing fields. Its purpose is to make a contribution in new non destructive techniques focusing in its development and application to real systems. Durability and damage evaluation in non-homogeneous materia...
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| Tipo de recurso: | tesis doctoral |
| Fecha de publicación: | 2018 |
| País: | España |
| Institución: | Consejo General de la Arquitectura Técnica de España (CGATE) |
| Repositorio: | RIARTE |
| OAI Identifier: | oai:www.riarte.es:20.500.12251/2328 |
| Acceso en línea: | http://hdl.handle.net/20.500.12251/2328 http://hdl.handle.net/10251/114799 |
| Access Level: | acceso abierto |
| Palabra clave: | Ensayos (propiedades o materiales) Ensayo No Destructivo (END) Ensayo con ondas mecánicas Material no homogéneo Hormigón Fibra de vidrio Resistencia a flexión Material compuesto Resistencia mecánica Espectrometría 3305.05 Tecnología del Hormigón 3305.33 Resistencia de Estructuras 3312.08 Propiedades de Los Materiales 3312.12 Ensayo de Materiales 3312.09 Resistencia de Materiales 2211.02 Materiales Compuestos 2201.01 Propiedades Acústicas de Los Sólidos |
| Sumario: | This doctoral thesis is developed in materials, Non-Destructive Testing (NDT) and signal processing fields. Its purpose is to make a contribution in new non destructive techniques focusing in its development and application to real systems. Durability and damage evaluation in non-homogeneous materials is the keystone of this document, assembling the structure in two main chapters. In the first instance the behaviour of Glass-fiber Reinforced Cement under bending test is evaluated. Multiple ultrasonic signals during the deformation process of the specimens were acquired, implementing a new multi-frequency acquisition technique. After the acquisition stage, linear and non-linear parameters were calculated from the pulsed ultrasonic signals correlating those parameters with the stress strain curve described during the test. In the third chapter, the impact spectroscopy analysis applied to chemical and thermal damaged mortar samples is exposed. The non-linear histeretic behaviour of the mortar specimens was studied more in depth. The analysis of the dynamic modulus softening with increment of the excitation amplitude is a hot spot at this moment for damage evaluation, being the current technique depending on the multiple signals acquisition. In this context, a new technique is proposed which allows a non-linear parameters extraction from a single reverberation signal. |
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