Design And Performance Analysis Of Fishing Line Flexure Hinge With Large Deformation

Flexible mechanisms have been widely used in biomimetic robot,intelligent structure,micro-electromechanical system and biomedical engineering,and have become a research hotspot in mechanical field.As an important part of flexible mechanisms,flexure hinges have been widely studied by researchers.Many scholars have proposed flexure hinge with different structures and materials.In order to enrich the types and shapes of flexure hinges and study the characteristics,manufacturing and application of flexure hinges,this paper designs a large deformation fishing line flexure hinge.The specific research content is as follows:The flexible ball hinge of single fishing line was designed,and the beam coefficient of circular section of the beam-constraint-model method was derived.The large deformation analysis model of the single fishing line flexible beam was established by using the chain spatial-beam-constraint-model method,and the influence of the change of the end load,length and radius of the flexible beam on the deformation of the flexible beam was analyzed.A flexure hinge with two beams arranged in parallel was designed and analyzed.The maximum stress and axial drift distance of the hinge were calculated,and the fatigue life of the hinge was analyzed.It is found that the change of the distance between two flexible beams has little influence on the deformation of the flexible beam,and the change of the Angle between two beams has great influence on the deformation of the hinge.Flexure hinges with the same flexible beams arranged in parallel,flexure hinges with different radii and biaxial hinges were designed.The influence of the number and radius of flexible beams on the deformation of the hinges was analyzed,and the influence of the length of the flexible beam at both ends and the rigid body in the middle on the deformation of the biaxial hinges was analyzed.It is found that the deformation of hinge with different radius is the deformation of flexible beam hinge with large radius.When the length of the first flexible beam of the biaxial hinge increases,the deformation of the hinge is larger than that of the middle rigid body.Three manufacturing processes for fishing line flexure hinges were proposed.Using the 3D printing manufacturing process,eight fishline hinges were manufactured,and the displacement of the fishline hinges was measured.It was found that the experimental measurement value had a small error compared to the theoretical calculation value and the simulation value.Compared to the theoretical value,the maximum error did not exceed15.43%,and compared to the simulation value,the maximum error did not exceed 16.02%,and the reasons for the significant errors were analyzed.A displacement amplification mechanism was fabricated using a fishwire hinge and driven by a piezoelectric stack.The displacement of the platform was measured and compared with that of a displacement amplification mechanism made of polylactic acid.A bionic eye device was fabricated using a fishline hinge and driven by a linear stepper motor to measure the rotation angle of the bionic eye.