Tensile strength grading of beech (Fagus sylvatica L.) lamellas from multiple origins, cross sections and qualities

The market share of European beech (Fagus sylvatica L.) wood in the construction sector is low despite an increase in beech stock in Central European Forests in recent years. More efficient sawing techniques, higher lamella grading yields and solving of adhesion challenges may increase the competitiveness of beech glulam and promote its use....

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...

Tensile Strength and Stiffness of Low Quality Beech (Fagus Sylvatica) Sawn Timber

This paper investigates the tensile strength and stiffness of low quality beech sawn timber. In addition, the influences of visual and physical characteristics of the beech boards on the mechanical performance were analysed. Visual characteristics like knots, pith or fibre deviation as well as density and dynamic modulus of elasticity were...

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...

Wood properties from roundwood to timber engineering

Measuring and assessing wood properties during the production chain is getting more and more important for an optimal use of the resource. Over the years, research has been performed with the focus on establishing important wood properties, with the final goal of an optimized use in timber engineering. It is...