Mechanics Performance Testing And Functional Analysis For Modified Halo Pelvic Distraction Fixture

Purpose:To analysis the structural characteristics of modified Halo pelvic distraction fixture, and test it's mechanical properties. To clarify it's working principle, make certain influence factors of it's traction, and delve the relationship between traction and displacement.Method:To simulate running conditions of modified Halo pelvic distraction fixture, divide it into three parts, test mechanical properties of them.The first,to measure loaded and unloaded displacement of Longitudinal strut bar's inter-fixed points.The second,to measure loaded and unloaded displacement of connection device's inter-fixed points.The third,to measure loaded and unloaded displacement of head ring's inter-fixed points.Finally, to draw load-displacement curve , summed up the principle and analysis mechanical properties by the theory of Engineering Mechanics and Mechanics Of Materials.Results:1.Progressive loading under 0 ~ 20kg load: Longitudinal strut bar's diameter group. D= 8mm group did not measure loaded and unloaded displacement inter-fixed points;D=5mm group measured loaded displacement 1.9mm and unloaded displacement 0.2mm inter-fixed points when loaded to 14kg;D=6mm group measured loaded displacement 1.7mm and unloaded displacement 0mm inter-fixed points when loaded to 20kg.It is linear between load and displacement.2.Progressive loading under 0 ~ 20kg load: Longitudinal strut bar's distance group. H=45mm group measured loaded displacement 0~0.5mm and unloaded displacement 0mm inter-fixed points;H=50mm group measured loaded displacement 0~0.9mm and unloaded displacement 0mm inter-fixed points;H=55mm group measured loaded displacement 0~1.7mm and unloaded displacement 0mm inter-fixed points. It is linear between load and displacement.3.Progressive loading under 0 ~ 20kg load: Longitudinal strut bar inter-fixed points' distance group.L=500mm group measured loaded displacement 0~1.7mm and unloaded displacement 0mm inter-fixed points;L=550mm group measured loaded displacement 0~1.7mm and unloaded displacement 0mm inter-fixed points;L=600mm group measured loaded displacement 0~1.8mm and unloaded displacement 0mm inter-fixed points;L=650mm group measured loaded displacement 0~2.0mm and unloaded displacement 0mm inter-fixed points;L=700mm group measured loaded displacement 2.7mm and unloaded displacement 0.2mm inter-fixed points when loaded to 20kg;L=750mm group measured loaded displacement 2.8mm and unloaded displacement 0.3mm inter-fixed points when loaded to 18kg;L=800mm group measured loaded displacement 3.0mm and unloaded displacement 0.3mm inter-fixed points when loaded to 16kg. It is linear between load and displacement.4.Progressive loading under 0 ~ 20kg load:Longitudinal strut bar's levers-type group.h'group measured loaded displacement 1.0mm and unloaded displacement 0.2mm inter-fixed points when loaded to 4kg;h group measured loaded displacement 2.2mm and unloaded displacement 0.3mm inter-fixed points when loaded to 8kg;H group measured loaded displacement 3.0mm and unloaded displacement 0.3mm inter-fixed points when loaded to 16kg.It is linear between load and displacement.5.Progressive loading under 0~200N load:connection device group measured loaded displacement 0~0.417mm and did not measure unloaded displacement inter-fixed points.It is linear between load and displacement.6.Progressive loading under 0~200N load: head ring group measured loaded displacement 0~0.433mm and did not measure unloaded displacement inter-fixed points. It is linear between load and displacement.Conclusion: When longitudinal strut bar's elastic modulus, diameter, offset distance, the distance between locking points and levers-type are definited,there is a linear relationshiip between load and displacement in modified Halo pelvic distraction...