Impact of spacing and pruning on quantity, quality and economics of Douglas-fir sawn timber: scenario and sensitivity analysis

Controlling the long-term effect of management on the quantity and properties of individual boards is a fundamental challenge for silviculture. Within this basic study on Douglas-fir, we have investigated the sensitivity of the net present value (NPV) to three most common planting densities and a prominent pruning strategy. We therefore have...

Analysis of economic feasibility of ash and maple lamella production for glued laminated timber

Background and Objectives: In the near future, in Europe a raised availability of hardwoods is expected. One possible sales market is the building sector, where medium dense European hardwoods could be used as load bearing elements. For the hardwood species beech, oak, and sweet chestnut technical building approvals already allow the production...

Development of an andvanced fe-numerical method for virtual grading of timber

Structural heterogeneities in wood are changing the complexity of the numerical modelling of this material. Knots are the main strength governing parameters, which are changing the uniformity of the stress distributions through the boards. These weak locations may result in failure in the material. Comprehensive reconstruction of the boards,...

Optimizing characteristic properties of visually graded soft- and hardwoods lamellas for the glulam production

For the production of lamellas for GLT or CLT visually or machine strength graded timber is required. Visual grading allows only for a limited number of classes while reject rates tend to be high. The present paper shows the potential of an evolutionary algorithm NSGA-II optimizing the boundaries of multiple visual grading criteria in a...

Species independent strength modeling of structural timber for machine grading

The current methods for the determination of the strength properties for wood species for grading purposes require extensive testing. Species independent grading might be a solution for this problem, in particular for tropical hardwoods. The strength reducing characteristics such as knots and slope of grain...

Species independent strength grading of structural timber

Timber as a construction material has been used for millennia, but the research field covering the prediction of the strength of structural timber is still in development. Currently, the common conception is that the determination of strength properties has to be determined for every wood species individually. By combining these strength...

Safety of timber: An analysis of quality control options

The quality assurance of timber properties is important for the safety of timber structures. In the current study, the quality control options of timber are analysed under the prism of the different growth regions. Therefore, these options - machine and output control - are simulated in accordance with EN 14081, and the performance is assessed...

The development of a strength grading system for small diameter roundwood

Roundwood as a construction material is becoming more and more interesting to users. Using this wood in construction will increase the value of the material and may open new opportunities for construction design. In order to use round wood for this application, suitable connectors andlor joints have to be developed, but before all, the strength...