Adhesive Bonding Formulas

Adhesive bonding formulas are covered in the following sections:

• Cycle Time Formulas for Adhesive Bonding

• Expendable Tooling for Adhesive Bonding

Cycle Time Formulas for Adhesive Bonding

Cycle Time = Process Time * Cycle Time Adjustment Factor

Cycle time is the product of the following:

• Process time (see formula)

• Cycle time adjustment factor: specified by the cost model variable cycleTimeAdjustmentFactor (1 in starting point VPEs). Administrators can customize this value in order to globally adjust cycle times.

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 adhesive is applied, expressed in square meters--see formula.

• Application Area Rate: the rate at which adhesive 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

The surface area to which adhesive is applied 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 which adhesive is applied. By default in starting point VPEs, this is 0.1. Administrators can customize the default, and specify the default percentage of total surface area by using the cost model variable defaultPercentBonded (10 in starting point VPEs). Users can override the default on a per-part basis, and specify a percentage of surface area with the setup option Bonded Area.

This value is converted to square meters for use in the formulas Bond Time and Degrease Time, as well as in the calculation for Expendable Tooling for Adhesive Bonding.

Degrease Time = Surface Area Bonded / Degrease Application Rate

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

• Surface area bonded: this is the surface area to be degreased, which is the surface area to which adhesive 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 for Adhesive Bonding

Expendable Tooling Cost Per Part =

Surface Area Bonded *

Resin Density *

Applied Resin Thickness *

Resin Material Factor *

Resin Material Price

This is the cost per part for adhesive resin. It is the product of the following:

• Surface Area Bonded: the surface area to which adhesive is applied, expressed in square meters--see the formula for Surface Area Bonded in Cycle Time Formulas for Adhesive Bonding.

• Resin density: density of the adhesive, specified in kg/m3 by the cost model variable resinDensity (1100kg/m3 in starting point VPEs).

• Applied resin thickness: this is the thickness of the coat of adhesive applied to the surfaces. It is specified in meters by the cost model variable defaultResinThickness (0.002m in starting point VPEs).

• Resin material factor: this factor adjusts the cost upward in order to account for adhesive that is lost during application. The factor is 1.1 in starting point VPEs, indicating that the volume of material lost is equal to 1/10th of the volume of material that is successfully applied to assembly surfaces. Administrators can customize the factor with the cost model variable resinMaterialFactor.

• Resin material price: this is the price per unit mass for adhesive, expressed in USD per Kg. It is looked up by adhesive type (Acrylic, Epoxy, or Urethane, in starting point VPEs) in the lookup table adhesiveResins. The adhesive type is Acrylic by default in starting point VPEs. Administrators can customize the default with the cost model variable defaultAdhesiveResin. Users can override the default on a per-part basis with the setup option Adhesive Resin Type.