What should be the slope of the roof to avoid stagnation? As with standard roof beams should be a continuous upward slope is equal to 1 / 4 inch / foot (20.8 mm / m) between the discharge and the peak of the roof, above the minimum recommended camber avoid stagnation.
In the case of sufficient slope that is less than 20.8 mm / m, we note that the stiffness of the supporting members or act 5lb/ft2 239.4 N/mm2 load does not cause the diversion of more than 1 / 2 inch or 12.7 mm What is stress and the radial curvature factor?
For a constant area of cross section of the radial force caused by bending moment in a Member State is calculated using this formula
fr = 3M/2Rbd
where
M = bending moment in lb (N m)
R = radius of center members, (mm)
b = width of cross section, in (mm)
d = depth of section, in. (mm)
When we have a curved portion, the curvature factor is introduced and is calculated as
Cc = 1000-2000 (T / R) 2
where
t is the thickness of rolling (mm)
R is the radius of curvature of the lamination (mm).
What Correction Factors Must Be Done In Design Values?
Its always some variation in the design values calculated by the wood. Therefore, we must apply the necessary adjustment for them.
The extreme fiber bending
Fb = FbCDCMCtCLCFCVCfuCrCcCf
where
FB - adjusted design value
Fb = value of extreme fiber bending
CD load duration factor =
CM = wet service factor
CCT = temperature coefficient
CL = beam stability factor
CF = factor measurement applies only to the visually classified sawn and round timber bending members
Cv = volume factor applies only when the rays are glued or laminated
Cfu = constant factor in the use of only one size of timber beams 2-4 (50.8 to 101.6 mm), and laminated wood beams
Cr = repetitive member factor applies only to the size of the beams, 2-4 (to101.6 50.8 mm) thick
Cc = curvature factor applies only to glulam beams curved parts
CF = form
When the bars are glued, laminated, we have to use smaller of the two-CL or CC
The design value of the voltage
Ft = FtCDCMCtCF
where
FT '- design value adjusted
Ft - Design value for the tension.
Adjustment for shear
Fv = FvCDCMCtCH
where
Fv '- Design adjusted value
Fv-value for the CH-cut design and is the shear factor> = 1 Fvparallel allow for the grain to the wood members.
Adjustments for compression perpendicular to the direction of
Fc1'is the value of the project
FC1 '= Fc1CDCtCb
where
Fc1is design value in compression perpendicular to grain
CB lubrication factor.
The value of the survey corrected for compression parallel to grain
FC = FcCDCMCtCFCp
where
Fc is a compression design value parallel to grain
CP Factor column stability.
Design value adjusted to bring the wood grain parallel to the end
FG '= FgCDCt
where
Fg is the design value for the fine grain, keeping parallel to the grain.
The adjusted value of the survey's modulus E '
E '= ECMCTC
where E = design value of the module
CT = buckling stiffness factor
C = correction factors appropriate
In the case of sufficient slope that is less than 20.8 mm / m, we note that the stiffness of the supporting members or act 5lb/ft2 239.4 N/mm2 load does not cause the diversion of more than 1 / 2 inch or 12.7 mm What is stress and the radial curvature factor?
For a constant area of cross section of the radial force caused by bending moment in a Member State is calculated using this formula
fr = 3M/2Rbd
where
M = bending moment in lb (N m)
R = radius of center members, (mm)
b = width of cross section, in (mm)
d = depth of section, in. (mm)
When we have a curved portion, the curvature factor is introduced and is calculated as
Cc = 1000-2000 (T / R) 2
where
t is the thickness of rolling (mm)
R is the radius of curvature of the lamination (mm).
What Correction Factors Must Be Done In Design Values?
Its always some variation in the design values calculated by the wood. Therefore, we must apply the necessary adjustment for them.
The extreme fiber bending
Fb = FbCDCMCtCLCFCVCfuCrCcCf
where
FB - adjusted design value
Fb = value of extreme fiber bending
CD load duration factor =
CM = wet service factor
CCT = temperature coefficient
CL = beam stability factor
CF = factor measurement applies only to the visually classified sawn and round timber bending members
Cv = volume factor applies only when the rays are glued or laminated
Cfu = constant factor in the use of only one size of timber beams 2-4 (50.8 to 101.6 mm), and laminated wood beams
Cr = repetitive member factor applies only to the size of the beams, 2-4 (to101.6 50.8 mm) thick
Cc = curvature factor applies only to glulam beams curved parts
CF = form
When the bars are glued, laminated, we have to use smaller of the two-CL or CC
The design value of the voltage
Ft = FtCDCMCtCF
where
FT '- design value adjusted
Ft - Design value for the tension.
Adjustment for shear
Fv = FvCDCMCtCH
where
Fv '- Design adjusted value
Fv-value for the CH-cut design and is the shear factor> = 1 Fvparallel allow for the grain to the wood members.
Adjustments for compression perpendicular to the direction of
Fc1'is the value of the project
FC1 '= Fc1CDCtCb
where
Fc1is design value in compression perpendicular to grain
CB lubrication factor.
The value of the survey corrected for compression parallel to grain
FC = FcCDCMCtCFCp
where
Fc is a compression design value parallel to grain
CP Factor column stability.
Design value adjusted to bring the wood grain parallel to the end
FG '= FgCDCt
where
Fg is the design value for the fine grain, keeping parallel to the grain.
The adjusted value of the survey's modulus E '
E '= ECMCTC
where E = design value of the module
CT = buckling stiffness factor
C = correction factors appropriate
