Three-point bending specimen clamping device for breaking tenacity testing

A three-point bending specimen clamping device for breaking tenacity testing comprises an upper clamp and a lower clamp. The upper clamp is arranged on an upper clamping head on a three-point bending tester, and the lower clamp is arranged on a lower clamping head on the three-point bending tester. Two supporting blocks are arranged on the lower clamp and arranged at the two ends of the lower clamp. A groove matched with a supporting roller for supporting a three-point bending specimen is formed in the end of each supporting block. According to the three-point bending specimen clamping device, the supporting rollers can roll only in the testing process and cannot move in the horizontal direction, and the span S is kept unchanged in the testing process, so that the finally-tested breaking tenacity precision is improved; the supporting rollers will not move outwards suddenly in the testing process, and it is ensured that a test is carried out in the quasi-static state, so that the testing result accuracy is improved; in the testing process, the supporting rollers are embedded into the supporting blocks, so that the phenomenon that operators are injured when the supporting rollers fly out is avoided, and the personal safety of the operators is protected.