Method for preparing tensile specimen of epoxy structural adhesive and vibration curing device

A method for preparing a tensile specimen of an epoxy structural adhesive, the method comprising:

• obtaining a colloid mixture by mixing an epoxy resin, an amine-curing agent, and a silane coupling agent, and putting the colloid mixture into a beaker, and putting the beaker in a water bath furnace with a constant temperature, and using a stirring device to stir the colloid mixture until the epoxy resin, the amine-curing agent, and the silane coupling agent are mixed evenly, wherein a weight ratio between the epoxy resin and the amine-curing agent is equal to A:B, and a weight ratio between the amine-curing agent and the silane coupling agent is equal to B:C, A is within 5 to 5.3, B is equal to 1, and C is within 0.2 to 0.4;
• putting the colloid mixture that is evenly mixed into a vacuum dryer, wherein the vacuum dryer starts to evacuate air with an environment temperature within a temperature range of 25° C. to 35° C., a working pressure inside the vacuum dryer is within −0.2 bar to −0.8 bar, and an evacuation time is within 1 minute to 2 minutes;
• cleaning oil stains on a surface of a tensile specimen mold by using aviation kerosene and industrial alcohol, and spraying a release agent on the cleaned tensile specimen mold two times, and using a needle to inject the colloid mixture into a molding groove of the tensile specimen mold and filling the molding groove, putting a pressing plate sprayed with release agent on the tensile specimen mold, fixing a plurality of buckles with the tensile specimen mold to fix the pressing plate and the tensile specimen mold together to form a whole mold, fixing the whole mold on a vibration platform of a vibration device through pressing strip to ensure that the whole mold vibrates at a same frequency as the vibration platform;
• turning on the vibration device to vibrate the whole mold, during vibration of the vibration device, a bubble in the structural adhesive is subjected to force of a vibration field, and a balance relationship of a pore of the structural adhesive is as follows:
• P
• v
• -
• P
• r
• -
• P
• v
• ⁢
• i
• ⁢
• b
• ⁢
• r
• =
• k
• ⁢
• σ
• v
• R
• v
• ,
• wherein Pv represents an internal pressure of the pore, Pr represents a hydrostatic pressure, Pvibr represents a pressure caused by the vibration field, k represents a surface tension coefficient, σv represents a pore surface tension, Rv represents a radius of the pore;
• after the vibration is finished, turning on an electric heating function of the vibration device to heat the whole mold from the environment temperature to a predetermined temperature range of 55° C. to 60° C. at a heating rate of 1° C./min, and keep warm at the temperature 60° C. for 480 minutes;
• then cooling with the vibration device, and finally performing demolding and obtaining the tensile specimen of the structural adhesive after vibration curing.