Ply Placing Operation for Hand Layup

Ply placing with hand layup is a labor-dependent task (see Labor-dependent and Labor-independent Tasks).

Labor Dependent Process Time =

(Ply Area / Ply Complexity Layup Rate) * Layup Guide Multiplier

Layup time depends on the following:

• Ply area: specified by the geometric property Surface Area. This is the area of one side of the ply, after cutouts have been removed.

• Ply complexity layup rate: this is the layup rate, adjusted for ply complexity. See formula.

• Layup guide multiplier: this is 1 if the current machine has a laser projection system. Otherwise, this is a factor greater than 1, reflecting the increased time required for layup using manual layup guides. The factor is specified by the cost model variable manualLayupGuideMultiplier (1.1 in starting point VPEs).

Complexity Ply Layup Rate =

Weighted Flexibility Rate +

Weighted Cutout Rate +

Weighted Deformation Rate

This is the layup rate, adjusted for three ply characteristics that affect layup rate:

• Ply material flexibility: a ply made of less flexible materials requires a slower layup rate.

• Ply cutouts: a ply with lots of perimeter and/or interior cutouts requires a slower layup rate.

• Ply deformation: a highly deformed ply requires a slower layup rate.

The adjusted value is somewhere between the minimum and maximum rate for plies of similar area to the current ply’s area. These maximum and minimum rates are calculated based on values looked up by Surface Area Filled in the lookup table tblPlyHandLayupTimes.

Complexity ply layup rate is a weighted sum of three different layup rates, each of which takes into account just one of the above ply characteristics (the weights add up to 1). That is, it is the sum of the following:

• Weighted flexibility rate (see formula)

• Weighted cutout rate (see formula)

• Weighted deformation rate (see formula)

You can generate a layup rate report by selecting Reports > SpreadSheet Reports... > Composites Report.

Weighted Flexibility Rate = Flexibility Weighting * Flexibility Rate

Weighted flexibility rate is the product of the following:

• Flexibility weighting: this reflects the relative importance of material flexibility to layup rate. It is a number between 0 and 1, specified by the cost model variable weightingHLUMaterialFlexibility (0.5 in starting point VPEs). Note that flexibility weighting, cutout weighting, and deformation weighting must sum to 1.

• Flexibility rate: this is the layup rate, taking into account material flexibility.

Material flexibility is specified by the material property Deformation Average Angle (which is the average of Deformation Limit Angle and Deformation Warning Angle).

Flexibility rate is somewhere between the minimum rate, Min Rate, and the maximum rate, Max Rate, for the ply’s area. Min Rate and Max Rate are calculated based on values looked up by Surface Area Filled in the lookup table tblPlyHandLayupTimes.

If material flexibility is some fraction of the way from the easiest-to-handle flexibility to the hardest-to-handle flexibility (for available materials), then flexibility rate is that fraction of the way from Max Rate to Min Rate.

For example, if material flexibility is halfway between the easiest-to-handle flexibility and the hardest-to-handle flexibility, then flexibility rate is halfway between Max Rate and Min Rate.

Weighted Cutout Rate = Cutout Weighting * Cutout Rate

Weighted cutout rate is the product of the following:

• Cutout weighting: this reflects the relative importance of cutouts to layup rate. It is a number between 0 and 1, specified by the cost model variable weightingHLUPlyCutout (0.1 in starting point VPEs). Note that flexibility weighting, cutout weighting, and deformation weighting must sum to 1.

• Cutout rate: this is the layup rate, taking into account ply cutouts.

The extent of cutouts is quantified by the cutout ratio, which is a ratio of geometric properties:

cutout ratio = Surface Area / Surface Area Filled

Surface Area Filled is the ply’s area plus the estimated area of interior and perimeter cutouts.

Cutout rate is somewhere between the minimum rate, Min Rate, and the maximum rate, Max Rate, for the ply’s area. Min Rate and Max Rate are calculated based on values looked up by Surface Area in the lookup table tblPlyHandLayupTimes.

If the cutout ratio is some fraction of the way from the easiest-to-handle ratio (1) to the hardest-to-handle ratio (0), then cutout rate is that fraction of the way from Max Rate to Min Rate.

For example, if the cutout ratio is halfway between the easiest-to-handle ratio to the hardest-to-handle ratio, then cutout rate is halfway between Max Rate and Min Rate.

Weighted Deformation Rate = Deformation Weighting * Deformation Rate

Weighted deformation rate is the product of the following:

• Deformation weighting: this reflects the relative importance of deformation to layup rate. It is a number between 0 and 1, specified by the cost model variable weightingHLUPlyDeformation (0.4 in starting point VPEs). Note that flexibility weighting, cutout weighting, and deformation weighting must sum to 1.

• Deformation rate: this is the layup rate, taking into account ply deformation.

The degree of deformation is quantified by a level between 1 and 5 (the higher the level, the greater the deformation). The level is determined based on the geometric properties Average Curvature, Curvature Deviation, and Max Curvature, and is intended to reflect a number of aspects of deformation, including the following:

o Degree of curvature: large curvature is harder to handle than mild curvature.

o Uniformity of curvature: varying curvature is harder to handle than overall, uniform curvature.

o Localization of curvature: distributed curvature (with multiple local extrema) is harder to handle than localized curvature.

See Ply Deformation Level for more information.

Deformation rate is somewhere between the minimum rate, Min Rate, and the maximum rate, Max Rate, for the ply’s area. Min Rate and Max Rate are calculated based on values looked up by Surface Area in the lookup table tblPlyHandLayupTimes.

If the deformation level is some fraction of the way from the easiest-to-handle level (1) to the hardest-to-handle level (5), then the deformation rate is that fraction of the way from Max Rate to Min Rate.

For example, if the deformation level is halfway between the easiest-to-handle level and the hardest-to-handle level, then the deformation rate is halfway between Max Rate and Min Rate.

Ply Material Cost =

(Ply Area / (Material Utilization / 100)) * Material Cost Per Unit Area

Material cost for a ply depends on the following:

• Ply area: specified by the geometric property Surface Area. This is the area of one side of the ply.

• Material utilization: this is the percentage of ply material that is used in parts and is not wasted. It is specified by the material property Material Utilization.

• Material cost per unit area: unit cost of ply material, specified in square meters by the material property Material Cost Per Area. This is converted to cost per square millimeter for use in this formula.