AWC-NDS materials

AWC-NDS wood construction materials

Wood construction materials according to
National Design Specification for Wood Construction 2018 Edition.

VERIFICATION TESTS REQUIRED!!!.

class materials.awc_nds.AWCNDS_materials.BeamMember(unbracedLength, section, connection=<materials.steel_member_base.MemberConnection object>)

Bases: materials.awc_nds.AWCNDS_materials.MemberBase

Beam member according to chapter 3.3 of NDS-2018.

getBeamStabilityFactor(numberOfConcentratedLoads=0, lateralSupport=False, cantilever=False)
Return the beam stability factor according to equation
3.3.6 of NDS-2018.
Parameters:
  • numberOfConcentratedLoads – number of concentrated loads equally spaced along the beam (0: uniform load).
  • lateralSupport – if true beam has a lateral support on each load.
  • cantilever – if true cantilever beam otherwise single span beam.
getBendingSlendernessRatio(numberOfConcentratedLoads=0, lateralSupport=False, cantilever=False)
Return the slenderness ratio according to equation
3.3-5 of NDS-2018.
Parameters:
  • numberOfConcentratedLoads – number of concentrated loads equally spaced along the beam (0: uniform load).
  • lateralSupport – if true beam has a lateral support on each load.
  • cantilever – if true cantilever beam otherwise single span beam.
getEffectiveLength(numberOfConcentratedLoads=0, lateralSupport=False, cantilever=False)
Return the effective length of the beam according to table
3.3.3 of NDS-2018.
Parameters:
  • numberOfConcentratedLoads – number of concentrated loads equally spaced along the beam (0: uniform load).
  • lateralSupport – if true beam has a lateral support on each load.
  • cantilever – if true cantilever beam otherwise single span beam.
getFbECriticalBucklingDesignValue(numberOfConcentratedLoads=0, lateralSupport=False, cantilever=False)
Return the critical bucking design value for bending according to
section 3.3.3.8 of NDS-2018.
Parameters:
  • numberOfConcentratedLoads – number of concentrated loads equally spaced along the beam (0: uniform load).
  • lateralSupport – if true beam has a lateral support on each load.
  • cantilever – if true cantilever beam otherwise single span beam.
class materials.awc_nds.AWCNDS_materials.ColumnMember(unbracedLengthB, unbracedLengthH, section, connection=<materials.steel_member_base.MemberConnection object>)

Bases: materials.awc_nds.AWCNDS_materials.MemberBase

Column member according to chapter 3.7 and 3.9 of NDS-2018.

getBSlendernessRatio()

Return the slenderness ratio for the B dimension.

getBendingSlendernessRatioB()

Return the slenderness ratio for bending in the B plane.

getBendingSlendernessRatioH()

Return the slenderness ratio for bending in the h plane.

getCapacityFactor(E_adj, Fc_adj, Fb1_adj, Fb2_adj, fc, fb1, fb2)
Return the capacity factor for members subjected to a
combination of bending about one or both principal axes and axial compression according to section 3.9.2 of NDS-2.018.
Parameters:
  • E_adj – adjusted modulus of elasticity for beam stability and column stability calculations.
  • Fc_adj – adjusted value of reference compression stress.
  • Fb1_adj – adjusted value of reference bending stress (for bending load applied to narrow face of member).
  • Fb2_adj – adjusted value of reference bending stress (for bending load applied to wide face of member).
  • fc – compression stress.
  • fb1 – bending stress (bending load applied to narrow face of member).
  • fb2 – bending stress (bending load applied to wide face of member).
getColumnStabilityFactor(c, E_adj, Fc_adj)
Return the column stability factor according
to expression 3.7-1 of NDS-2.018.
Parameters:
  • E_adj – adjusted modulus of elasticity for beam stability and column stability calculations.
  • Fc_adj – adjusted compression stress design value parallel to grain.
  • c – 0.8 for sawn lumber, 0.85 for round timber poles and piles and 0.9 for structural glued laminated timber structural composite lumber, and cross-laminated timber.
getEffectiveBucklingLengthCoefficientRecommended()

Return the column effective buckling length coefficients according to NDS 2018 appendix G

getFbE(E_adj)
Return the value of F_{bE} as defined in section
3.9.2 of NDS-2.018.
Parameters:E_adj – adjusted modulus of elasticity for beam stability and column stability calculations.
getFcE1(E_adj)
Return the value of F_{cE1} as defined in section
3.9.2 of NDS-2.018.
Parameters:E_adj – adjusted modulus of elasticity for beam stability and column stability calculations.
getFcE2(E_adj)
Return the value of F_{cE2} as defined in section
3.9.2 of NDS-2.018.
Parameters:E_adj – adjusted modulus of elasticity for beam stability and column stability calculations.
getHSlendernessRatio()

Return the slenderness ratio for the H dimension.

getSlendernessRatio()

Return the slenderness ratio.

getUnbracedLengthB()

Return the B unbraced length.

class materials.awc_nds.AWCNDS_materials.CustomLumberSection(name, b, h, woodMaterial)

Bases: materials.sections.section_properties.RectangularSection

Section of a lumber member with custom dimensions.

defElasticShearSection2d(preprocessor, overrideRho=None)
Defines a elastic shear section for two-dimensional
problems.
Parameters:
  • preprocessor – pre-processor for the finite element problem.
  • overrideRho – if defined (not None), override the value of the material density.
defElasticShearSection3d(preprocessor, overrideRho=None)
Defines a elastic shear section for three-dimensional
problems.
Parameters:
  • preprocessor – pre-processor for the finite element problem.
  • overrideRho – if defined (not None), override the value of the material density.
getBendingFlatUseFactor()

Return the flat use factor for the bending design value Fb.

getBendingSizeFactor()

Return the size factor for the bending design value Fb.

getCompressionSizeFactor()

Return the size factor for the compression design value Fc.

getEAdj()

Return the adjusted value of E.

getEminAdj()

Return the adjusted value of Emin.

getFb()
getFbAdj(Cr=1.0)

Return the adjusted value of Fb.

Parameters:Cr – repetitive member factor
getFcAdj()

Return the adjusted value of Fc.

getFc_perpAdj(Cb=1.0)

Return the adjusted value of Fc_perp.

Parameters:Cb – bearing area factor
getFtAdj()

Return the adjusted value of Ft.

getFvAdj()

Return the adjusted value of Fv.

getTensionSizeFactor()

Return the size factor for the tension design value Ft.

class materials.awc_nds.AWCNDS_materials.DimensionLumberSection(name, woodMaterial)

Bases: materials.awc_nds.AWCNDS_materials.CustomLumberSection

Section of a dimension lumber member.

class materials.awc_nds.AWCNDS_materials.HeaderSection(name, b, h, Ms, Vs, linearDensity, wood)

Bases: materials.sections.section_properties.RectangularSection

Structural beam/header.

defElasticShearSection2d(preprocessor, overrideRho=None)
Defines a elastic shear section for two-dimensional
problems.
Parameters:
  • preprocessor – pre-processor for the finite element problem.
  • overrideRho – if defined (not None), override the value of the material density.
defElasticShearSection3d(preprocessor, overrideRho=None)
Defines a elastic shear section for three-dimensional
problems.
Parameters:
  • preprocessor – pre-processor for the finite element problem.
  • overrideRho – if defined (not None), override the value of the material density.
defXCMaterial(overrideRho=None)

Defines the material in XC.

Parameters:overrideRho – if defined (not None), override the value of the material density.
getFb()
getLinearDensity()

Return the mass per unit length.

nu = 0.2
class materials.awc_nds.AWCNDS_materials.LSL(name='LSL')

Bases: materials.awc_nds.AWCNDS_materials.Wood

Base class for laminated strand lumber (LSL)

getFb(depth)
Return the allowable bending stress given
the member depth.
Parameters:depth – member depth.
class materials.awc_nds.AWCNDS_materials.LSLHeaderSection(name, b, h, Ms, Vs, linearDensity, wood)

Bases: materials.awc_nds.AWCNDS_materials.HeaderSection

LSL structural beam/header.

getVolumeFactor()

Return volumen factor.

class materials.awc_nds.AWCNDS_materials.LSL_135E(name='LSL_135E')

Bases: materials.awc_nds.AWCNDS_materials.LSL

LSL 1.35E.

E = 9307926000.0
Emin = 9307926000.0
Fb_12 = 11927934.8
Fc_perp = 5171070.0
Fc_pll = 11376354.0
Fv = 2826851.6
getFb(depth)
Return the allowable bending stress given
the member depth.
Parameters:depth – member depth.
xc_material_name = 'LSL_135E'
class materials.awc_nds.AWCNDS_materials.LSL_135E_HeaderSection(name, b, h, Ms, Vs, linearDensity)

Bases: materials.awc_nds.AWCNDS_materials.LSLHeaderSection

LSL 1.35E structural beam/header.

class materials.awc_nds.AWCNDS_materials.LSL_155E(name='LSL_135E')

Bases: materials.awc_nds.AWCNDS_materials.LSL

LSL 1.35E.

E = 10686878000.0
Emin = 10686878000.0
Fb_12 = 16271633.6
Fc_perp = 6032915.0
Fc_pll = 14996103.0
Fv = 2826851.6
xc_material_name = 'LSL_155E'
class materials.awc_nds.AWCNDS_materials.LSL_155E_HeaderSection(name, b, h, Ms, Vs, linearDensity)

Bases: materials.awc_nds.AWCNDS_materials.LSLHeaderSection

LSL 1.55E structural beam/header.

class materials.awc_nds.AWCNDS_materials.LVLHeaderSection(name, b, h, Ms, Vs, linearDensity, wood)

Bases: materials.awc_nds.AWCNDS_materials.HeaderSection

LVL structural beam/header.

getVolumeFactor()

Return volumen factor.

class materials.awc_nds.AWCNDS_materials.LVL_2900Fb2E(name='LVL_2900Fb2E')

Bases: materials.awc_nds.AWCNDS_materials.LSL

LVL 2900Fb 2.0E structural.

E = 13789520000.0
Emin = 13789520000.0
Fb_12 = 19994804.0
Fc_perp = 5171070.0
Fc_pll = 22063232.0
Fv = 1965006.6
xc_material_name = 'LVL_2900Fb2E'
class materials.awc_nds.AWCNDS_materials.LVL_2900Fb2E_HeaderSection(name, b, h, Ms, Vs, linearDensity)

Bases: materials.awc_nds.AWCNDS_materials.LVLHeaderSection

LVL 2900Fb 2.0E structural beam/header.

class materials.awc_nds.AWCNDS_materials.MemberBase(unbracedLength, section, connection=<materials.steel_member_base.MemberConnection object>)

Bases: object

Base class for beam and column members according to chapter 3 of NDS-2018.

class materials.awc_nds.AWCNDS_materials.OSBPanelSection(name, b, h, shear_constant)

Bases: materials.awc_nds.AWCNDS_materials.WoodPanelSection

Oriented strand board panel.

defElasticShearSection2d(preprocessor, angle=1.5707963267948966, overrideRho=None)
Defines a elastic shear section for two-dimensional
problems.
Parameters:
  • preprocessor – pre-processor for the finite element problem.
  • angle – angle of the stress with the strength axis.
  • overrideRho – if defined (not None), override the value of the material density.
getE(angle=1.5707963267948966)
Return the bending stress Fb or the panel according
to the table A of the document: “Design Capacities for Oriented Strand Board V1.0 – 01/2008” from PFS TECO • 1507 Matt Pass, Cottage Grove, WI 53527, USA
Parameters:angle – angle of the stress with the strength axis.
getFb(angle=1.5707963267948966)

Return the bending stress Fb or the panel according to the table A of the document: “Design Capacities for Oriented Strand Board V1.0 – 01/2008” from PFS TECO • 1507 Matt Pass, Cottage Grove, WI 53527, USA

angle: angle of the stress with the strength axis.

getFv()

Return the bending stress Fb or the panel according to the table A of the document: “Design Capacities for Oriented Strand Board V1.0 – 01/2008” from PFS TECO • 1507 Matt Pass, Cottage Grove, WI 53527, USA

rho = 632.62
class materials.awc_nds.AWCNDS_materials.PlywoodPanelSection(name, b, h, shear_constant)

Bases: materials.awc_nds.AWCNDS_materials.WoodPanelSection

Plywood structural panel.

rho = 577.941243312
class materials.awc_nds.AWCNDS_materials.Wood(name, specificGravity=None)

Bases: materials.wood_base.Wood

Base class for wood materials according to AWC-NDS2018.

getDowelBearingStrength(diameter, theta, endGrain=False)
Return the dowel bearing strength for Dowel-Type
Fasteners in Wood Members according to Eq. 12.3-11 and table 12.3.3 of National Design Specification of the American Wood Council
Parameters:
  • diameter – diameter of the dowel-type fastener.
  • theta – angle between the direction of load and the direction of grain (longitudinal axis of member).
  • endGrain – true for dowel-type fasteners with D > 1/4” that are inserted into the end grain of the main member, with the fastener axis parallel to the wood fibers. See clause 12.3.3.4 of NDS.
class materials.awc_nds.AWCNDS_materials.WoodPanelSection(name, b, h, shear_constant)

Bases: materials.sections.section_properties.RectangularSection

Wood structural panel.

getAPARatedSturdIFloor()

Return the APA rated Sturd-I-Floor from the panel thickness according to the table B of the documents: “Design Capacities for Oriented Strand Board V1.0 – 01/2008” and “Design Capacities for Structural Plywood V1.0 – 01/2008” both from PFS TECO • 1507 Matt Pass, Cottage Grove, WI 53527, USA

getArealDensity()

Return the mass per unit area (thickness= h).

getSpanRating()

Return the span rating from the panel thickness according to the table B of the documents: “Design Capacities for Oriented Strand Board V1.0 – 01/2008” and “Design Capacities for Structural Plywood V1.0 – 01/2008” both from PFS TECO • 1507 Matt Pass, Cottage Grove, WI 53527, USA

materials.awc_nds.AWCNDS_materials.convertToCelsius(fahrenheit)

Convert to Celsius degrees.

materials.awc_nds.AWCNDS_materials.convertToFahrenheit(celsius)

Convert to Fahrenheit degrees.

materials.awc_nds.AWCNDS_materials.getFireDesignAdjustementFactor(refValue)
Return the format conversion factor (LRFD) according to table 16.2.2
of AWC-NDS2018.
Parameters:refValue – reference design values (Fb, FbE, Ft,Fc, and FcE)
materials.awc_nds.AWCNDS_materials.getFormatConversionFactor(refValue, connection=False)
Return the format conversion factor (LRFD) according to table 2.3.5
of AWC-NDS2018.
Parameters:
  • refValue – reference design values (Ft,Emin,Fb,Fv, Frt,Fs,Fc and FcT)
  • connection – connection design (True or False)
materials.awc_nds.AWCNDS_materials.getLoadDurationFactor(duration)

Return load duration factor according to table 2.3.2 of AWC-NDS2018.

Parameters:duration – duration of the load (years)
materials.awc_nds.AWCNDS_materials.getResistanceFactor(refValue, connection=False)
Return the format conversion factor (LRFD) according to table 2.3.6
of AWC-NDS2018.
Parameters:
  • refValue – reference design values (Ft,Emin,Fb,Fv, Frt,Fs,Fc and FcT)
  • connection – connection design (True or False)
materials.awc_nds.AWCNDS_materials.getTemperatureFactor(refValue, moisture, fahrenheit)

Return the temperature factor according to table 2.3.3 of AWC-NDS2018.

Parameters:
  • refValue – reference design values (Ft,E,Emin,Fb,Fv,Fc and FcT)
  • moisture – moisture (dry or wet)
  • fahrenheit – temperature (fahrenheit degrees)
materials.awc_nds.AWCNDS_materials.getVolumeFactor(L, b, h, southernPine=False)
Return the volume factor according to clause 5.3.6
of AWC-NDS2018.
Parameters:
  • L – length of bending member between points of zero moment (m).
  • b – width of bending member (m).
  • d – depth of bending member (m).
materials.awc_nds.AWCNDS_materials.getWetServiceFactor(refValue, moistureContent, sawnLumber=False)

Return the wet service factor according to AWC-NDS2018.

Parameters:
  • refValue – reference design values (Ft,E,Emin,Fb,Fv,Fc and FcT)
  • moistureContent – moisture content (%)
  • sawnLumber – True or False

Dimensional lumber reference design values

Dimensional lumber reference design values.

class materials.awc_nds.dimensional_lumber.DimensionLumberWood(name=None, grade='', sub_grade='', rho=None, wet=False)

Bases: materials.awc_nds.AWCNDS_materials.Wood

Dimensional lumber material.

defXCMaterial()

Defines the material in XC.

fb_size_factor_interp_3 = <scipy.interpolate.interpolate.interp1d object>
fb_size_factor_interp_4 = <scipy.interpolate.interpolate.interp1d object>
fb_size_factor_x = [1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 8.0, 10.0, 12.0, 14.0, 1000.0]
fb_size_factor_y3 = [1.5, 1.5, 1.5, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.9]
fb_size_factor_y4 = [1.5, 1.5, 1.5, 1.5, 1.4, 1.3, 1.3, 1.2, 1.1, 1.0, 1.0]
fc_size_factor_interp = <scipy.interpolate.interpolate.interp1d object>
fc_size_factor_x = [1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 8.0, 10.0, 12.0, 14.0, 1000.0]
fc_size_factor_y = [1.15, 1.15, 1.15, 1.15, 1.1, 1.1, 1.05, 1.0, 1.0, 0.9, 0.9]
flat_use_interp_3 = <scipy.interpolate.interpolate.interp1d object>
flat_use_interp_4 = <scipy.interpolate.interpolate.interp1d object>
flat_use_x = [1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 8.0, 10.0, 1000.0]
flat_use_y3 = [1.0, 1.0, 1.0, 1.1, 1.1, 1.15, 1.15, 1.2, 1.2]
flat_use_y4 = [1.0, 1.0, 1.0, 1.0, 1.05, 1.05, 1.05, 1.05, 1.1]
getBendingFlatUseFactor(b, h)

Return the flat use factor for the bending design value Fb according to National Design Specification table 4A.

getBendingSizeFactor(b, h)

Return the size factor for the bending design value Fb according to National Design Specification table 4A.

getCompressionSizeFactor(b, h)

Return the size factor for the compression design value Ft according to National Design Specification table 4A.

getEAdj()

Return the adjusted value of E according to National Design Specification table 4A.

getEminAdj()

Return the adjusted value of Emin according to National Design Specification table 4A.

getFb(h)

Return the value of Fb. Used in BeamMember.getBeamStabilityFactor

Parameters:h – section depth
getFbAdj(b, h, Cr=1.0)
Return the adjusted value of Fb according
to National Design Specification table 4A.
Parameters:Cr – repetitive member factor
getFcAdj(b, h)

Return the adjusted value of Fc according to National Design Specification table 4A.

getFc_perpAdj(Cb=1.0)
Return the adjusted value of Fc_perp according
to National Design Specification table 4A.
Parameters:Cb – bearing area factor
getFtAdj(b, h)

Return the adjusted value of Ft according to National Design Specification table 4A.

getFvAdj()

Return the adjusted value of Fv according to National Design Specification table 4A.

getTensionSizeFactor(b, h)

Return the size factor for the tension design value Ft according to National Design Specification table 4A.

getXCMaterialName()

Return the name for create the corresponding XC material.

stud_fb_size_factor_interp = <scipy.interpolate.interpolate.interp1d object>
stud_fb_size_factor_x = [1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 8.0]
stud_fb_size_factor_y = [1.1, 1.1, 1.1, 1.1, 1.0, 1.0, 1.0]
stud_fc_size_factor_interp = <scipy.interpolate.interpolate.interp1d object>
stud_fc_size_factor_x = [1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 8.0]
stud_fc_size_factor_y = [1.05, 1.05, 1.05, 1.05, 1.0, 1.0, 1.0]
class materials.awc_nds.dimensional_lumber.DouglasFirLarchWood(name='DouglasFirLarch', grade='no_2', sub_grade='')

Bases: materials.awc_nds.dimensional_lumber.DimensionLumberWood

Douglas Fir-Larch refence design values according to table 4A of National Design Specification page 34.

nu = 0.2
class materials.awc_nds.dimensional_lumber.SouthernPineWood(name='SouthernPine', grade='no_2', sub_grade='')

Bases: materials.awc_nds.dimensional_lumber.DimensionLumberWood

Southern Pine reference design values based on SPIB grading rules and AWC National Design Specification

getFb(h)

Return the value of Fb. Used in BeamMember.getBeamStabilityFactor

Parameters:h – section depth
nu = 0.2
class materials.awc_nds.dimensional_lumber.SprucePineFirWood(name='SprucePineFir', grade='no_2', sub_grade='')

Bases: materials.awc_nds.dimensional_lumber.DimensionLumberWood

Spruce-pine-fir refence design values according to table 4A of National Design Specification page 37.

nu = 0.2

Dowel type fasteners

Dowel type fasteners design according to chapter 12 of “NATIONAL DESIGN SPECIFICATION FOR WOOD CONSTRUCTION 2018” of the American Wood Council.

class materials.awc_nds.dowel_type_fasteners.DowelFastener(diameter, length, tip, bendingYieldStrength)

Bases: object

Dowel-Type fastener as defined in chapter 12 of NDS-2018.

Variables:
  • diameter – fastener diameter.
  • length – fastener length.
  • tip – fastener tapered tip length.
  • bendingYieldStrength – fastener bending yield strength (see table I1 NDS-2018).
getDiameterForYield()

Return the diamterer to use in the k1, k2 and k3 expressions accorcing to clause 12.3.7 of NDS-2018.

getK1(mainMemberWood, sideMemberWood, lm, ls, theta_m, theta_s, endGrain=False)
Return the k1 factor according to table
12.3.1B of NDS-2018.
Parameters:
  • mainMemberWood – main member Wood object.
  • mainMemberWood – side member Wood object.
  • lm – main member dowel bearing length.
  • ls – side member dowel bearing length.
  • theta_m – angle between the direction of load and the direction of grain of the main member.
  • theta_s – angle between the direction of load and the direction of grain of the side member.
  • endGrain – true for dowel-type fasteners with D > 1/4” that are inserted into the end grain of the main member, with the fastener axis parallel to the wood fibers. See clause 12.3.3.4 of NDS.
getK2(mainMemberWood, sideMemberWood, lm, ls, theta_m, theta_s, endGrain=False)
Return the k2 factor according to table
12.3.1B of NDS-2018.
Parameters:
  • mainMemberWood – main member Wood object.
  • mainMemberWood – side member Wood object.
  • lm – main member dowel bearing length.
  • ls – side member dowel bearing length.
  • theta_m – angle between the direction of load and the direction of grain of the main member.
  • theta_s – angle between the direction of load and the direction of grain of the side member.
  • endGrain – true for dowel-type fasteners with D > 1/4” that are inserted into the end grain of the main member, with the fastener axis parallel to the wood fibers. See clause 12.3.3.4 of NDS.
getK3(mainMemberWood, sideMemberWood, lm, ls, theta_m, theta_s, endGrain=False)
Return the k3 factor according to table
12.3.1B of NDS-2018.
Parameters:
  • mainMemberWood – main member Wood object.
  • mainMemberWood – side member Wood object.
  • lm – main member dowel bearing length.
  • ls – side member dowel bearing length.
  • theta_m – angle between the direction of load and the direction of grain of the main member.
  • theta_s – angle between the direction of load and the direction of grain of the side member.
  • endGrain – true for dowel-type fasteners with D > 1/4” that are inserted into the end grain of the main member, with the fastener axis parallel to the wood fibers. See clause 12.3.3.4 of NDS.
getPenetration(sideMemberThickness)

Return the dowel penetration in the main member.

Parameters:sideMemberThickness – side member thickness.
getReductionTerm(theta, yieldMode)
Return the reduction term Rd according to table
12.3.1B of NDS-2018.
Parameters:
  • theta – maximum angle between the direction of load and the direction of grain (0<=theta<=PI/2) for any member in a connection.
  • yieldMode – yield mode.
getYieldLimit(mainMemberWood, sideMemberWood, lm, ls, theta_m, theta_s, doubleShear=False, endGrain=False)
Return the yield limit according to table
12.3.1B of NDS-2018.
Parameters:
  • mainMemberWood – main member Wood object.
  • mainMemberWood – side member Wood object.
  • lm – main member dowel bearing length.
  • ls – side member dowel bearing length.
  • theta_m – angle between the direction of load and the direction of grain of the main member.
  • theta_s – angle between the direction of load and the direction of grain of the side member.
  • doubleShear – double shear plane in connection.
  • endGrain – true for dowel-type fasteners with D > 1/4” that are inserted into the end grain of the main member, with the fastener axis parallel to the wood fibers. See clause 12.3.3.4 of NDS.
class materials.awc_nds.dowel_type_fasteners.LagScrew(diameter, length, tip, rootDiameter, bendingYieldStrength=310264200.0)

Bases: materials.awc_nds.dowel_type_fasteners.Screw

Lag screw as defined in NDS-2018.

getDesignWithdrawal(G, sideMemberThickness, endGrainFactor=0.75)
Return the withdrawal design value based on main
member penetration.
Parameters:
  • G – specific gravity of wood.
  • sideMemberThickness – side member thickness.
  • endGrainFactor – applicable where lag screws are loaded in withdrawal from end grain (see section 12.2 of NDS-2018.
getMinPenetration()

Return the minimum length of lag screw pentration, p_min, including the length of the tapered tip where part of the penetration into the main member for single shear connections and the side members for double shear connection according to clause 12.1.4.6 of NDS-2018.

getReferenceWithdrawal(G)
Return reference withdrawal design value according
to equation 12.2-1 of NDS-2018.
Parameters:G – specific gravity of wood.
class materials.awc_nds.dowel_type_fasteners.Nail(diameter, length, hardenedSteel=False)

Bases: materials.awc_nds.dowel_type_fasteners.DowelFastener

Nail as defined in NDS-2018.

getDesignWithdrawal(G, sideMemberThickness)
Return the withdrawal design value based on main
member penetration.
Parameters:
  • G – specific gravity of wood.
  • sideMemberThickness – side member thickness.
getMinPenetration()

Return the minimum length of nail pentration, p_min, including the length of the tapered tip where part of the penetration into the main member for single shear connections and the side members for double shear connection according to clause 12.1.6.4 of NDS-2018.

getReferenceWithdrawal(G)
Return reference withdrawal design value according
to equation 12.2-3 of NDS-2018.
Parameters:G – specific gravity of wood.
class materials.awc_nds.dowel_type_fasteners.Screw(diameter, length, tip, rootDiameter, bendingYieldStrength=310264200.0)

Bases: materials.awc_nds.dowel_type_fasteners.DowelFastener

Screw as defined in NDS-2018.

Variables:rootDiameter – root diameter.
class materials.awc_nds.dowel_type_fasteners.WoodScrew(diameter, length, headDiameter, rootDiameter, threadLength=None, bendingYieldStrength=310264200.0)

Bases: materials.awc_nds.dowel_type_fasteners.Screw

Wood screw as defined in NDS-2018.

Variables:
  • headDiameter – head diameter.
  • threadLength – thread length.
getDiameterForYield()

Return the diameter to use in the k1, k2 and k3 expressions accorcing to clause 12.3.7 of NDS-2018.

getMinPenetration()

Return the minimum length of wood screw pentration, p_min, including the length of the tapered tip where part of the penetration into the main member for single shear connections and the side members for double shear connection according to clause 12.1.5.6 of NDS-2018.

Lumber types specific gravity

Specific gravity according to table 12.3.3A from “NATIONAL DESIGN SPECIFICATION FOR WOOD CONSTRUCTION 2018” of the American Wood Council.

Structural_panels

Properties of Plywood structural panels taken from: http://www.pfsteco.com/techtips/pdf/tt_plywooddesigncapacities table C.

Oriented strand board panels according to document: “Panel design specification” Form No. D510C/Revised May 2012/0300

Properties of LSL beams and headers taken from: LP SolidStart LSL Beam & Header Technical Guide

Properties of LVL beams and headers taken from: LP SolidStart LVL Beam & Header Technical Guide