Structural analysis of two King-post timber trusses: Non-destructive evaluation and load-carrying tests

Abstract

The misunderstanding of the overall behaviour of traditional timber trusses can result in incorrect strengthening interventions or, frequently, on their replacement. Timber roof structures need a more concise knowledge of the real behaviour to determine internal loads and control the load transfer. For that, laboratory tests on scaled or full-scale specimens of members, connections and trusses are needed. In this paper, an accurate geometric and mechanical evaluation of the timber elements of two King-post timber trusses, based on grading results with data gathered from non-destructive tests (NDT), including mechanical evaluation of the modulus of elasticity in bending (MoE), followed by full-scale carrying tests were performed. The trusses were reassembled in laboratory and submitted to a series of symmetric and non-symmetric cyclic tests, according to the Limit States. Strengthening techniques evaluated in precedent research steps were used in a second phase of the load-carrying tests.

Research on residual bending capacities of used wood members based on the correlation between non-destructive testing results and the mechanical properties of wood

“…Visual inspections are the basis of any analysis of traditional timber structures (Branco et al, 2010). The classifications of rot and infestation for measure points are respectively classified as follows according to Chinese regulation GB/T 13942.…”

Assessment of timber floors by means of non-destructive testing methods

“…Resistance drilling enables to locate defects and structural discontinuities in timber members without affecting the performance, which is particularly important in the case of heritage structures [32,33].…”

Empleo del penetrómetro para madera para el diagnóstico de la madera en servicio en edificios antiguos

“…Señalan que el empleo del Pilodyn 6J es eficaz para definir áreas con alteraciones, permitiendo realizar un mapeo de las mismas en los elementos estructurales, que requieren posteriores prospecciones por medios más sofisticados, como el empleo del resistógrafo, a fin de acotar la sección residual del elemento. En otro trabajo, el profesor Piazza (26) junto con otros investigadores de la universidad de Minho, analizan dos cerchas de madera mediante NDT y pruebas de carga, en los que incluyen el instrumento Pilodyn obteniendo medidas en las cuatro caras de los elementos estructurales, a fin de localizar zonas de menor densidad acotando posibles alteraciones del material. Los NDT empleados han sido la microperforación, ensayos de penetración, auscultaciones de ultrasonidos y evaluaciones mecánicas a fin de tener valores de módulo de elasticidad estático.…”