Abstract: A method for in-situ non-contact detection of a symmetry error of a keyway located on the shaft-type workpiece includes the following steps: establishing a detection system and a system calculation coordinate system; controlling rotation of a shaft-type workpiece, continuously acquiring data of a detection part by means of a laser displacement sensor, and calculating and analyzing the acquired data to obtain a symmetry error of a detection section; and moving the laser displacement sensor in an axis direction, and calculating symmetry errors of a plurality of sections of the keyway, to obtain a symmetry error of the keyway located on the shaft-type workpiece.

Abstract: A resilient prestress-free steel structure includes the elastic centering beam and two pin-ended box column bases. The elastic centering beam includes two cantilever segment I-shaped steel beams, a middle segment I-shaped steel beam and buckling restrained high strength steel bars. The cantilever segment I-shaped steel beams are fixed to the two pin-ended box column bases, the middle segment I-shaped steel beam is connected between the two cantilever segment I-shaped steel beams, the buckling restrained high strength steel bars are symmetrically arranged. One end of each of the buckling restrained high strength steel bars is firmly connected with the web of each of the cantilever segment I-shaped steel beams, and the other end of each of the buckling restrained high strength steel bars is firmly connected with the web of the middle segment I-shaped steel beam. The resilient prestress-free steel structure is arranged in left and right symmetrical manner.

Abstract: The present invention discloses an in-place non-contact detection method for a shaft workpiece. The method includes: establishing a detection system, calibrating the detection system and establishing a detection coordinate system; analyzing a pose of a workpiece in the detection system to establish a coordinate system of a workpiece clamping device; controlling the workpiece clamping device of a shaft workpiece processing machine tool to rotate, continuously acquiring data by a linear laser measuring instrument, and calculating and analyzing the acquired data to obtain an ideal reference axis of the shaft workpiece; continuously acquiring data of a detection part, and calculating and analyzing the acquired data to obtain actual machining precision of runout of a shaft neck of a camshaft; and continuously acquiring data of the detection part, and calculating and analyzing the acquired data to obtain machining precision of coaxiality of the shaft workpiece.

Abstract: A resilient prestress-free steel structure includes the elastic centering beam and two pin-ended box column bases. The elastic centering beam includes two cantilever segment I-shaped steel beams, a middle segment I-shaped steel beam and buckling restrained high strength steel bars. The cantilever segment I-shaped steel beams are fixed to the two pin-ended box column bases, the middle segment I-shaped steel beam is connected between the two cantilever segment I-shaped steel beams, the buckling restrained high strength steel bars are symmetrically arranged. One end of each of the buckling restrained high strength steel bars is firmly connected with the web of each of the cantilever segment I-shaped steel beams, and the other end of each of the buckling restrained high strength steel bars is firmly connected with the web of the middle segment I-shaped steel beam. The resilient prestress-free steel structure is arranged in left and right symmetrical manner.