WSU HYPER Strain Gauge Workshop скачать в хорошем качестве

WSU HYPER Strain Gauge Workshop

Instructions on mounting strain gages to ASTM D638 Type V PA840-GSL composite samples Materials PA840-GSL Test Specimen Isopropyl Alcohol GSP-1 Gauze Sponges Strain Gage 320 Grit Silicone-Carbide Paper M-Prep Conditioner A CSP-1 Cotton Applicators M-Prep Neutralizer 5A PDT-3 Drafting Tape M-Bond 610 Resin M-Bond 610 Curing Agent Disposable Mixing Funnels Brush Caps MJG-2 Mylar Tape TFE-1 Teflon Film Silicone Gum Pad RSK Rosin Solvent Antimony Solder 326-DFV 3-Conductor Leadwire Surface Preparation: Retrieve (1) large aluminum plate. Tape plate down. Clean plate surface with GC-6 Isopropyl alcohol and GSP-1 gauze sponge. Dry surface with a heat gun on the low setting to ensure complete solvent removal. Solvent Application: Remove (1) strain gage from mylar envelope with tweezers and place on the aluminum plate with solder tabs facing up. Retrieve (1) PA840-GSL test specimen. Place on the aluminum plate. Apply isopropyl alcohol to the entire composite surface and strain gage surface with GSP-1 gauze sponge. Blot dry with clean, dry GSP-1 gauze sponge. Surface Abrasion: Abrade composite surface with 320 grit silicone-carbide paper. Continue to abrade until a matte finish is achieved (10-12 strokes). Dry surface of composite with a heat gun on the low setting to ensure complete solvent removal. Layout Lines: Utilize a pencil and straight edge to mark the surface of the composite sample with crossed reference lines where strain measurements are to be made. Lines shall be perpendicular to one another with one line oriented along the direction of strain measurement. Conditioning: Warm surface of composite with a heat gun on the low setting. Apply M-Prep conditioner A to composite and strain gage with CSP-1 cotton applicator until the clean tip is no longer discolored. Keep surfaces constantly wet with conditioner during conditioning step. Remove conditioner with a single stroke of GSP-1 gauze sponge prior to the conditioner drying. Neutralizing: Liberally apply neutralizer 5A to cleaned composite and strain gage surfaces. Scrub the surfaces with CSP-1 cotton applicator. Keep surfaces constantly wet with neutralizer during neutralization operation. Remove neutralizer with a single stroke of GSP-1 gauze sponge prior to the neutralizer drying. Note: Be sure to apply and remove conditioner and neutralizer as quickly as possible to prevent absorption. Strain Gage Cutting: Secure strain gage to aluminum plate with PDT-3 drafting tape. Cut strain gage along the perimeter of the foil pattern with precision knife. Be sure to leave a minimum distance of 5 mil between the cut and the foil pattern. Remove drafting tape. Solvent clean strain gage surface with isopropyl alcohol. Adhesive Preparation: Ensure M-Bond 610 resin and curing agent are at room temperature. Utilizing a plastic funnel, empty contents of “curing agent” bottle into “adhesive” bottle. Tighten the brush cap and thoroughly shake the adhesive bottle for 10 seconds. Mark the bottle with the date mixed. Allow to stand for (1) hour prior to its application. Strain Gage Preparation: While holding the gage in place with a mylar envelope, place a short length of MJG-2 mylar tape down over half of the gage tabs and the entire terminals. Strain Gage Application: Remove the gage assembly by peeling the tape at a shallow angle (about 30˚) and transfer to the specimen. The soldering tabs should face the number side of the specimen. Ensure the triangular index marks are aligned with the reference lines created in operation 130. Adhesive Application: By lifting at a shallow angle, peel back one end of the taped assembly to raise the gage and terminal. Coat the gage backing, terminal, and specimen surface with a thin layer of M-Bond 610 adhesive. Do not allow the adhesive applicator to touch the tape mastic. Air dry for 5 to 30 minutes at 75˚F and 50% relative humidity. Strain Gage Securement: Return the gage assembly to its original position over the layout marks. Apply only enough pressure to ensure assembly is tacked down. Overlay the gage/terminal area with a piece of TFE-1 Teflon film. Place (1) silicone gum pad piece and (1) small aluminum plate over the strain gage. Cure: Apply clamping force of 30 to 40 psi with the HSC spring clamp. Place the clamped specimen into a cool oven and raise the temperature to 325˚F at a rate of 5˚F to 20˚F per minute. Cure for a minimum of (2) hours at a minimum of 325˚F. Allow the oven to drop to at least 100˚F before removing the specimen. Remove clamping pieces and mylar tape. Note:Do not exceed cure temperature of 392˚F. This is the melting temperature of the PA11 matrix. Soldering: Wash off gage area with RSK rosin solvent to remove residual mastic and other contamination. Blot dry with GSP-1 gauze. Retrieve soldering iron, antimony solder, wet cloth, wire strippers, and leadwire. Cut (1) 1.5’ length of leadwire. Strip both ends of leadwire length. Tin the solder iron. Solder each leadwire to the solder tabs.