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Study On Mechanical Properties Of Kelp And Design Of Mechanisms For Knotting Kelp

Posted on:2019-02-23Degree:MasterType:Thesis
Country:ChinaCandidate:T C ChenFull Text:PDF
GTID:2381330596460377Subject:Mechanical engineering
Abstract/Summary:PDF Full Text Request
The kelp knot is a very popular food due to its good appearance and convenience for eating,which contributes to its high price in all kelp products.At present,the production of kelp knots is almost entirely done by hand with low productive efficiency in poor production environments.In order to realize the automatic knotting of kelp and improve the production efficiency of kelp knots,experimental study on the mechanical properties of kelp is conducted and mechanisms for knotting kelp based on the principle of D-knotting is designed in the subject.Expectable goals,including revealing the mechanical properties of kelp,studying the knotting principle of D-knotting and designing a kelp–knot mechanism,need to be achieved.Around these goals above,some studying results are listed as follows:Tension and friction experiments are employed to study biomechanics and friction properties of kelp under different test conditions.Experimental results show that most breaks are neat with obvious local deformation while the minority ruptures arise from a small gap on one side of samples.It is also found that the tensile speed and the thickness of samples have different effects on the tensile properties of kelp.The elastic modulus is significantly affected by the applied tensile speed and stress-strain curves can be fitted well by the quadratic equation.Kelp is proved to be viscoelastic through stress relaxation and creep tests.The friction coefficient between kelp and test materials is influenced by several factors,including the normal pressure,sample thickness,loading speed,relative displacement and test materials.In addition,it is also demonstrated that silica gel has a good performance with a lager friction coefficient and less surface damage to kelp in various friction tests,and silica gel is suitable to be applied in the grasp device of automatic equipment for kelp.This work is beneficial to the understanding of biomechanics and friction properties of kelp and the design of key parts of automatic processing machines.A kelp-knot mechanism composed of cams,incomplete gears and multiple links is designed based on the principle of D-knotting.The cooperation between the components ensures the completion of the knotting action.The overall solution design,timing design,transmission design and key components design are all implemented.The three-dimensional model of the kelp-knot mechanism is created after the design of structural parameters by Pro/E.And a rigid body dynamics simulation model is established by ADAMS to analyze the trajectory of multiple links and the time sequence of each component,in order to verify the rationality of the design of the kelp-knot mechanism.Non-linear dynamic contact simulation between the incomplete gear on the drive gear disc and the bevel gear is performed by ANSYS Workbench,in order to simulate and verify the contact stress of the first tooth on the incomplete gear.The simulation results show that the contact stress meets the design requirement.In addition,modal analysis of the drive gear disc and the press cam disc are carried out to verify the stability of the two drive discs during operation.
Keywords/Search Tags:Kelp, Mechanical properties, Physical design, Dynamics simulation, Finite element analysis
PDF Full Text Request
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