偏振光片颜色的含义

How to read Polarimeter (Photoelasticity ) BD • Sim •15-Jun-06 • Page 2 PCS APAC What is Photoelasticity? ƒ A non-destructive means of determining internal or residual stress in a transparent or translucent part using polarized light BD • Sim •15-Jun-06 • Page 3 PCS APAC Internal Stress Chart •It is important to understand the sequence of colors in order to evaluate internal stress •Tints of Passages are sharp dividing zones that can assist in determining levels of stress •Stress is highly dependent on material and thickness Increasing Stress 1mm 0.040in 0 0 0 160 1.9 276 260 3.1 449 345 4.1 596 460 5.5 794 520 6.2 898 620 7.4 1071 700 8.3 1209 800 9.5 1381 935 11.1 1614 1050 12.5 1813 1350 16.1 2331 1440 17.1 2486 1520 18.1 2624 1800 21.4 3108 2100 25.0 3626 2400 28.6 4144 1730 2300 Relative Retardation (nm) 575 1150 Pink Green Color Purple (Tint of Passage) Pink/Green Transition Green Green-Yellow Red Orange Dull Red Deep Blue Green Blue-Green Green Yellow Orange RoseRed 3971 Purple (Tint of Passage) Red/Green Transition Black Gray White 20.6 2987 27.4 Pale Yellow Stress in PC (MPa / psi) 13.7 1986 6.8 993 BD • Sim •15-Jun-06 • Page 4 PCS APAC Example •Select a point of interest (POI) •Visually evaluate the magnitude of stress at POI relative to the other part(s) Pale Yellow is lower on the spectrum than Deep Blue so the part on the right is more highly stressed.