Fay Sealing Formulas

Cycle Time =

(Process Time / Number of Operators) * Cycle Time Adjustment Factor

Cycle time depends on the following:

• Process time (see formula)

• Number of operators (specified by the machine property Number of Operators).

• Cycle time adjustment factor: specified by the cost model variable cycleTimeAdjustmentFactor; 1 in aPriori starting point VPEs. If you want to model an unbalanced, push assembly line, set cycleTimeAdjustmentFactor to a value greater than 1 in order to account for the cost of extra buffer capacity.

Process Time = Bond Time + Degrease Time

Process time is the sum of the following:

• Bond time (see formula)

• Degrease time (see formula)

Bond Time = Surface Area Bonded / Application Area Rate

This is the time to apply adhesive to the relevant surfaces of the assembly components. It depends on the following:

• Surface Area Bonded: the surface area to which sealant is applied, expressed in square meters--see formula.

• Application Area Rate: the rate at which sealant is applied. This is specified in m2/minute by the machine property Application Rate, and is converted to m2/sec for use in this formula.

Surface Area Bonded = Assembly Surface Area * Bonded Area

Surface area bonded is the product of the following:

• Assembly surface area: this is the sum of the surface areas of all the assembly's component parts (as determined by geometry extraction).

• Bonded area: this is the fraction of the total assembly surface area to be bonded. By default, this is specified by the cost model variable defaultPercentBonded (10% in starting point VPEs). Users can override the default with the setup option Bonded Area.

Note that this value is converted to square meters for use in the cycle time and expendable tooling formulas.

Degrease Time = Surface Area Bonded / Degrease Application Rate

This is the time to prepare the surface for the application of sealant. It depends on the following:

• Surface area bonded: this is the surface area to be degreased, which is the surface area to which sealant is subsequently to be applied--see formula, above.

• Degrease Application Rate: the rate at which degreasing solution is applied. This is specified in m2/minute by the cost model variable degreaseApplicationRate, (0.03 m2/minute in starting point VPEs), and is converted to m2/sec for use in this formula.

Expendable Tooling Cost = Surface Area Bonded * Sealant Density *

Applied Resin Thickness * Resin Material Factor * Sealant Material Price

Expendable tooling cost is the product of the following:

• Surface area bonded: See formula. Note that this value is converted to square meters for use in this formula.

• Sealant density: specified by the cost model variable sealantDensity (1570 kg/m3 in starting point VPEs).

• Applied resin thickness: specified by the cost model variable defaultResinThickness (0.002 meters, in starting point VPEs).

• Resing material factor: accounts for the loss of material during application. This is specified by the cost model variable resinMaterialFactor (1.1 in starting point VPEs).

• Sealant material price: by default this is looked up by Sealant Type in the lookup table sealant. Users can override the default with the setup option Sealant Price.