Material library

Diamonds comes with a library of standard materials. Apart from the characteristics, you can also find the resistance properties of the materials there.

You can adjust the material library using the menu ‘Edit – Material library …‘. The following dialogue appears:

• In the middle, you will find a list of all the defined materials.
  • Materials preceded by the icon are standard materials. It is not possible to edit standard materials. However, you can copy a standard material using . You’ll be able to edit the copy.
  • Materials preceded by the icon are user defined.
  • If a material is used in the current project, the button will light up when you select the material.
  • If you want a user material to be available during the entire session ( = until you close Diamonds), click the button .
  • If you want the user material to be always available in the library, hit the button .
  • Use the button or the right mouse button to set the default steel, concrete or timber quality.
• On the right, you will find the corresponding properties. The properties are ordered in 3 tab pages:
  • the mechanical properties
  • the thermal properties
  • the advanced properties
• The buttons on the left allow you to adjust the content of the library.
  • Click to save all changes.
  • Sort the materials in alphabetic order by clicking and . If you prefer the materials to appear in different order, you can drag and drop them with the mouse.
  • Click to add a new material.
  • Click to remove the selected material.
  • Click to copy the selected material. You can now adjust the material.
  • Click to see the number of materials.
• The buttons on bottom allow you to import / export the library.
  • Export the content of the current library with .
  • Import an external library with .
• The filter on the left allows you to determine which materials should be visible in the dialogue .

Mechanical properties

The mechanical properties are used in the elastic analysis .

• the name of the selected element
• Indicate which type the material belongs to. If you select steel, concrete or timber, you also need to indicate the resistance properties so that it is possible to conduct an additional verification. For all other materials, Diamonds performs only an elastic analysis of the structure. Then you can obtain the results of inner forces and stresses (elastic), but not of an additional specific verification.
• the Young’s elasticity modulus E, the Poison ratio ν, the transverse Young’s modulus G
• In the presence of an elastic material, there is a definite link between the first three properties. Thus, you can automatically calculate the transverse modulus using after E and ν have been determined.
• the thermal dilatation coefficient α
• the density ρ

Thermal properties

The thermal properties are used in a fire safety analysis .

• Thermal capacity c
• Thermal conductivity λ
• Emissivity ε_res

The thermal capacity and thermal conductivity depend on the temperature. This relationship is known for all materials in advance of the icon. For concrete, these two properties also depend on the concrete composition.

If you want to impose a function for the heat capacity or thermal conductivity:

• Select ‘Custom’ from the pull-down list.
• Click on . The following dialogue appears:

• Give the function a name.
• Then define the function by dragging the red squares.
  • deletes a point
  • ‘fluent’ interpolation between points. The points are being connected through a cubic spline.
  • linear interpolation between points. The points are being connected through straight.
  • adds a point, before the current and half way with the previous one.
  • adds a point, after the current and half way with the next one.
  • pastes an external table with value from the clipboard.
• With the button and you can import and export the curve.

Advanced properties

The advanced properties are used in a steel , concrete or timber design . We focus on the parameters for Eurocode without a national annex.

• Standard
  Select the design code from the drop-down menu for which you want to inspect or edit the material properties.

Advanced parameters for concrete

fck	Eurocode distinguishes different resistance classes, for example C25/30. The letter C stands for ‘concrete’. The first number represents the characteristic compressive strength of a concrete cylinder to compression (cylinder of 150mm x 300mm) after 28 days. This is fck. The second number represents characteristics of a concrete cube (cube of 150mm) after 28 days.
fctm	the average tensile strength after 28 days for resistance classes <C50/60 for resistance classes C50/60
Ecm	the Young’s elasticity modulus (which is given in the tab page ‘Mechanical properties’)
	the partial safety factor on the characteristic concrete strength
	the creep factor for limiting the stresses It is determined in such a way that:     Read here why there are two creep factors.
	the creep factor for calculating the cracked deformation is the default value, but you’re free to change it. Specific values are given in EN 1992-1-1 §3.1.4. Read here why there are two creep factors.
k1	the limiting factor on the concrete stresses in SLS RC to avoid unacceptable cracking and high creep levels (EN 1992-1-1 §7.2) = 0.60
k2	the limiting factor on the concrete stresses in SLS QP to avoid unacceptable cracking and high creep levels (EN 1992-1-1 §7.2) = 0.45

fyk	the characteristic yielding strength of the longitudonal reinforcement
fywk	the characteristic yielding strength of the transverse reinforcement (= the stirrups)
	the partial safety factor on the characteristic yielding strength of the reinforcement =1.15
k3	the limiting factor on the stresses in the reinforcement steel in SLS RC to avoid unacceptable cracking and high creep levels (EN 1992-1-1 §7.2) = 0.80
ρmin	the minimum tensile reinforcement ratio (EN 1992-1-1 §9) for beams for columns
ρmax	the maximum reinforcement ratio (EN 1992-1-1 §9) =0.04

Advanced parameters for steel

fy	the characteristic yielding strength The yielding & ultimate strength decrease when the dimensions of the cross-section increase. This is because larger dimensions increase the likelihood of residual stresses. Residual stresses have a negative effect on the yielding/ultimate strength.
fu	the characteristic ultimate strength The yielding & ultimate strength decrease when the dimensions of the cross-section increase. This is because larger dimensions increase the likelihood of residual stresses. Residual stresses have a negative effect on the yielding/ultimate strength.
	the partial safety factor on the characteristic yielding strength for calculating the resistance of cross-sections =1.0
	the partial safety factor on the characteristic yielding strength for calculating the member stability =1.0
until	the partial safety factors relevant for connection design (EN 1993-1-8) in PowerConnect

Advanced parameters for timber

ft,0,k	the characteristic tensile strength in fiber direction
fc,0,k	the characteristic compressive strength in fiber direction
ft,90,k	the characteristic tensile strength perpendicular to the fiber direction
fc,90,k	the characteristic compressive strength perpendicular to the fiber direction
fm,k	the characteristic bending strength
fv,k	the characteristic shear strength
	the partial safety factor on the strength properties
kmod	is a modification factor that takes the effect of the load duration and climate conditions on the strength properties into account (more info)
kdef	is a modification factor that takes the effect of the climate conditions on the stiffness properties into account (more info)