Presentation is loading. Please wait.

Presentation is loading. Please wait.

Development of a Digital Standard to Specify Surface Requirements

Similar presentations


Presentation on theme: "Development of a Digital Standard to Specify Surface Requirements"— Presentation transcript:

1 Development of a Digital Standard to Specify Surface Requirements
Michelle Voelker Frank Peters Paul Kemper Iowa State University Industrial & Manufacturing Systems Engineering SFSA Technical & Operating Conference December 10-12, 2015

2 Terminology Abnormality- an anomaly of the surface exceeding two-times the baseline roughness Abnormality Percentage- the percentage of the specified surface area containing abnormalities Baseline Roughness- the roughness average of surface excluding abnormalities Underlying Geometry- the surface geometry in absence of surface roughness and abnormalities E3- Expansion 3 things we are going to specify, and 1 thing that will give us a standard way to calculate these things we specified.

3 Terminology Abnormality- an anomaly of the surface exceeding two-times the baseline roughness Abnormality Percentage- the percentage of the specified surface area containing abnormalities Baseline Roughness- the roughness average of surface excluding abnormalities Underlying Geometry- the surface geometry in absence of surface roughness and abnormalities E3- Expansion 3 things we are going to specify, and 1 thing that will give us a standard way to calculate these things we specified.

4 Terminology Abnormality- an anomaly of the surface exceeding two-times the baseline roughness Abnormality Percentage- the percentage of the specified surface area containing abnormalities Baseline Roughness- the roughness average of surface excluding abnormalities Underlying Geometry- the surface geometry in absence of surface roughness and abnormalities E3- Expansion 3 things we are going to specify, and 1 thing that will give us a standard way to calculate these things we specified.

5 Proposed Standard Goal not to completely automate inspection; goal to create tool to verify visual inspection and automate qualification process.

6 Proposed Standard Determine underlying geometry
Calculate deviations from underlying geometry Set bounds on abnormalities at twice the baseline roughness Measure parameters from standard Goal not to completely automate inspection; goal to create tool to verify visual inspection and automate qualification process. Abnormal Points Baseline Roughness

7 Proposed Standard VSR Notation VSR 1.2 – 2.4 –5 Default Values
Baseline Abnormality Abnormality Roughness (mm) Level (mm) Percentage VSR 1.2 – 2.4 –5 Default Values Abnormality Level = 2x Baseline Roughness Abnormality Percentage = 5% Does not include chaplets/inserts, unusual visual conditions, dimensional accuracy

8 Surface Specification
How can we specify this surface profile? VSR 1.85 – – VSR 2.32 – – 17 VSR 6.00 – – 0 Baseline Roughness ↑, Abnormality Percentage ↓ Baseline Roughness ↓, Abnormality Percentage ↑ VSR 1.85 – 12– 35 VSR 2.32 – 12 – 17 Exact Classification VSR 6 – 12 – 0 Only want to specify range of abnormality (+/- 12) Abnormality Level has to be at least 12 Abnormality Percent must be > # point further than 2*Baseline Roughness / Total number of points

9 Surface Specification
How can we specify this surface profile? VSR 1.85 – – VSR 2.32 – – 17 VSR 6.00 – – 0 Baseline Roughness ↑, Abnormality Percentage ↓ Baseline Roughness ↓, Abnormality Percentage ↑ VSR 1.85 – 12– 35 VSR 2.32 – 12 – 17 Exact Classification VSR 6 – 12 – 0 Only want to specify range of abnormality (+/- 12) Abnormality Level has to be at least 12 Abnormality Percent must be > # point further than 2*Baseline Roughness / Total number of points

10 Surface Specification
How can we specify this surface profile? VSR 1.85 – – VSR 2.32 – – 17 VSR 6.00 – – 0 Baseline Roughness ↑, Abnormality Percentage ↓ Baseline Roughness ↓, Abnormality Percentage ↑ VSR 1.85 – 12– 35 VSR 2.32 – 12 – 17 Exact Classification VSR 6 – 12 – 0 Only want to specify range of abnormality (+/- 12) Abnormality Level has to be at least 12 Abnormality Percent must be > # point further than 2*Baseline Roughness / Total number of points

11 Surface Specification
How can we specify this surface profile? VSR 1.85 – – VSR 2.32 – – 17 VSR 6.00 – – 0 Baseline Roughness ↑, Abnormality Percentage ↓ Baseline Roughness ↓, Abnormality Percentage ↑ VSR 1.85 – 12– 35 VSR 2.32 – 12 – 17 Exact Classification VSR 6 – 12 – 0 Only want to specify range of abnormality (+/- 12) Abnormality Level has to be at least 12 Abnormality Percent must be > # point further than 2*Baseline Roughness / Total number of points

12 Surface Specification
How can these specifications be interpreted? VSR 6.00 – – 0

13 Surface Specification
How can these specifications be interpreted? VSR 1.85 – – 35 VSR 2.32 – – 17

14 Surface Specification
E3 SCRATA Comparator Sample VSR 0.06 –

15 Surface Measurement Localized Roughness Shape Fitting
Flat surface example for standard roughness algorithms

16 Surface Measurement Localized Roughness Shape Fitting D5- Curvature

17 Surface Measurement Localized Roughness Shape Fitting
E3- Flat surface on top of the abnormality

18 Surface Measurement Underlying Geometry: Slicing Method
Segment Point Cloud into Slices and Data into Single Line Fit Curve to 2D Segments of Data Create Surface across Curves A lot of parts have shrinkage and imperfect geometries so there is a need to find the underlying geometry for these calculations. It’s not a problem to reverse engineer the original part of find the roughness EXCEPT when abnormalities are present.

19 Triangulate Subsampled Cloud to Create Surface
Surface Measurement Underlying Geometry: Subsampling Method Subsample Point Cloud Triangulate Subsampled Cloud to Create Surface A lot of parts have shrinkage and imperfect geometries so there is a need to find the underlying geometry for these calculations. It’s not a problem to reverse engineer the original part of find the roughness EXCEPT when abnormalities are present.

20 Future Work Investigate point density requirements for each classification Compare point clouds to underlying geometry Improved accuracy of roughness calculations Improved isolation of abnormalities List of suggested acceptance levels based on industry castings Automated tool for checking standard on casting


Download ppt "Development of a Digital Standard to Specify Surface Requirements"

Similar presentations


Ads by Google