In-situ assessment of timber structures using non-destructive testing

Start date 01/07/2009
End date The project is closed: 01/07/2014
​Existing structures often require diagnostic investigations in order to ascertain their actual state and to assess their safe continuous use. This is particularly necessary for historical buildings but also for recent buildings and bridges when damaged by long-term lack of maintenance, poor design, poor workmanship or events like fires and floods.

The replacement of deteriorated members may not be an acceptable option for structures of historical significance and re-design may be necessary to sustain the functionality of the structure. This project will focus on technical challenges associated with the in-situ evaluation of timber in structures. The principal objective of the project is to develop guidelines and recommendations for performing assessments of existing timber structures using non-destructive (ND) methods with reference to their condition and structural capability.


Some specific sub-objectives are:

  • To provide the means for screening the existing timber structures for potential problem areas
  • To provide images of the internal condition of timber members and connections using NDT methods, such as advanced radiography, and to be able to interpret the results in a satisfactory way
  • To propose procedures to determine the load paths and structural behaviour and model the behaviour of various existing structures using material parameters determined with NDT methods 
  • The accuracy of the assessment will be determined by numerical modeling using the input data from various NDT methods and from static tests. Once the model is verified, various parametric studies will be performed in order to determine the accuracy of the NDT techniques and to propose a procedure to perform the assessments
  • Design models and guidelines for assessing timber structures (morphological inspection of structures) will be proposed.

Ongoing research and sub-projects: 

  • Estimation of state of stress using resonance frequency
  • Non-destructive investigation and determination of mechanical parameters on oak from the Vasa-warship.
  • Density calibration using X-ray equipment.  
  • Exploring the limitations of X-ray investigations.
  • Literature studies in the mentioned research fields


Other information

International research activity(-ies) in the field of non-destructive testing on structural timber:


The project is carried out at the Division of Structural Engineering in the researchgroup Steel and Timber Structures.

Keywords: In-situ assessment, non-destructive testing (NDT), semi-destructive testing (SDT), density determination, X-ray, calibration procedure, Vasa warship

Project members

Project leader
Prof. Dr. Rober Kliger

Prof. Dr. Robert Kliger (supervisor, examiner)
Dr. Ylva Sandin (supervisor, consultant/SP)
Dr. Daniel Sandin (supervisor. consultant/Dynalyse)
Thomas Lechner (doctoral student)

Thomas Lechner, Robert Kliger
Chalmers Areas of Advance

​Built Environment

Materials Science

The Swedish Research Council FORMAS

In-kindbudget: Stiftelsen Nils och Dorthi Troëdssons forskningsfond

Page manager Published: Mon 28 Oct 2013.