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RSPUNSURI SUBIECTE CONSTRUCII DIN LEMNlimba engleza

1. The physical characteristics of wood are determined for the ideal wood with amoisture content of 12% and they are:

- Density ( kg/mc);- Moisture content (%);- Contraction and swelling ;- Thermal proprierties (thermal conductivity, thermal dilatation, specific

heat);

- Behaviour to high temperatures2. Wooden members subjected to uniaxial bending are calculated to:

- Design resistance in bending:m,d = crit x fm,d

- Shearing cross the grains in supports or in critical sections whereconcentrate forces are applied:

d

- Shearing in the neutral axis:

d

- Compression cross the grains in supports:c,90,d kc,90 x fc,90,d

- Serviceability limit states verification, limiting the initial and finaldeflections:

Uinst Uadmis

Ufin Uinst x (1+ kdef) Uadm

For biaxial bending the verification is :

or

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3. Timber framings used for roofs depends on the construction transversal span.They are:

- Timber framings with a single purlin (ridge purlin);- Timber framings with one purlin on each slope;- Timber framings with one purlin on slope and a ridge purlin;- Timber framings with many purlins on each slope.Timber framings members are:

- Posts (columns);- Bearing elements for posts;- Purlins longitudinaly disposed ;- Rafters along the roof slope- Roof boarding as support for roof covering;- Transversal bracings;- Longitudinal bracings.

4. Timber framings used for roofs for constructions with vertical longitudinalstructural elements depends on the transversal span of the

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construction.

Timber framings members are:

- Posts (columns), vertical and inclined;- Bearing elements for posts;- Purlins (of ridge, intermediary) longitudinaly disposed and standing on

posts;

- Rafters along the roof slope- Roof boarding as support for roof covering;

5. The floors with timber beams have the structure made from:- Equidistant beams standing on vertical structural elements (walls, frames)- Connections elementsThe beams have 3-5 m spans and they are disposed to 70-120 cm between

them.

The beams may be disposed on one direction, or on one direction principal

beams, respectively secondary beams on the other direction.

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The beams may be:

- Solid timber beams;- Beams with solid timber flanges and a thick web;- Beams with solid timber web and thick flanges;- Trusses ;- Glued laminated beams (with constant or variable section)

The connection elements may be:

- Disposed on the superior part of the beams- Disposed on the superior part and inferior part of the beams- Between beams