Partial modal analysis for health assessment of living trees

Research output: Chapter in Book/Report/Conference proceedingPaper in conference proceeding


Rot in living trees cause substantial losses for the forestry industry. The common practice when evaluating forest stands for, e.g., purchase, is assessment based on visual signs. In this paper a new non-destructive assessment method based on the impact excitation method is proposed. The trunk of a living tree is excited by the impact of a hammer, and the vibrations are measured by accelerometers. Resonance frequencies, circumferential mode shapes and propagation velocity of a surface wave are analysed. A function describing the expected frequency for a sound tree is derived, and used in a detector whose performance is evaluated for 93 trees of species Norway spruce. The partial mode shape is used to ensure that the corresponding resonance frequencies are compared to each other. It is found that the detector is successful and outperforms assessments by skilled experts in forestry.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Other Electrical Engineering, Electronic Engineering, Information Engineering
Original languageEnglish
Title of host publicationAsia-Pacific conference on non-destructive testing (APCNDT)
Publication statusPublished - 2001
Publication categoryResearch
Event10th Asia-Pacific Conference on Non-Destructive Testing - Brisbane, Australia
Duration: 2001 Sep 172001 Sep 21


Conference10th Asia-Pacific Conference on Non-Destructive Testing