Sökning: "tracheid effect"
Visar resultat 1 - 5 av 6 avhandlingar innehållade orden tracheid effect.
1. Modelling and strength grading of structural timber and glulam lamellae on the basis of optical scanning and dynamic excitation
Sammanfattning : Machine strength grading of sawn timber is a sawmill process in which density, modulus of elasticity (MOE) and bending or tensile strength are predicted such that the timber can be assigned to strength classes. The predictions of these properties are performed using one or several so-called indicating properties (IPs), which represent a board property, or combination of board properties, measured non-destructively. LÄS MER
2. Local variation in bending stiffness in structural timber of Norway spruce : for the purpose of strength grading
Sammanfattning : Most strength grading machines on the European market use an averagemodulus of elasticity (MOE), estimated on a relatively large distance along awood member, as the indicating property (IP) to bending strength. Theaccuracy of such grading machines in terms of coefficient of determination israther low at R2 ≈ 0.5. LÄS MER
3. Studies of the fibre direction and local bending stiffness of Norway spruce timber : for application on machine strength grading
Sammanfattning : Machine strength grading is a production process in the sawmill industry used to grade sawn timber boards into different strength classes with specific characteristic values of the bending strength, modulus of elasticity (MOE) and density. These properties are called grade determining properties. LÄS MER
4. Automatic measurement of compression wood and spiral grain for the prediction of distortion in sawn wood products
Sammanfattning : Distortion is one of the major obstacles for effective utilisation of wood, especially in the building process, where wood has lost market shares to other materials largely because of the lack of straightness. Bow and spring are often caused by compression wood, while twist is the cause of spiral grain. LÄS MER
5. Image based methods for nondestructive detection of compression wood in sawn timber
Sammanfattning : Compression wood is an anomaly in wood formed by the living softwood tree to compensate for excessive, asymmetric loads by developing special fibres. Compression wood has special properties that are unwanted in the utilisation of sawn wood products and is thus desirable to detect and reject in an early stage. LÄS MER