Failure analysis of the toothed rollers of a coconut shell shredder machine through the simulation of harmonic response and transient structural state applying Ansys software

Abstract

Introduction: In Ecuador, the annual production of coconut is approximately 26,000 tons and its cultivation occurs in the provinces of Esmeraldas, Manabí, and Guayas. The process involved in peeling it is artisanal and almost rudimentary, causing people who are dedicated to this activity to have an elevated risk of accidents. Objective: The objective of this article is to perform a failure analysis of the toothed rollers of a coconut shell shredding machine by simulating harmonic response and transient structural state by applying the Ansys software, as a contribution to the coconut industrial sector. Results: the design and construction of the machine is shown in a general way, while, for the development of the objective of this research, the design and plan of the toothed rollers were presented. The simulation of the rollers was conducted in the Ansys software, for which; parameters of the system and mesh size of 4, 6 and 10 mm were established; with the purpose of obtaining its natural fundamental frequency, frequency response, deformations, and von Mises stresses. In the analysis of harmonic response and transient structural state, as the mesh size decreases, the values of maximum total strain and maximum von Mises stress are increasingly accurate, having accuracy in the 4 mm mesh with values of 0.07393 mm and 15.86 MPa, respectively. Conclusion: It is concluded that, in the simulation by harmonic response of the rollers, the frequency of 35 Hz reaches its maximum excitation with an amplitude value of 1.039e-10 mm, not generating damage in them, while, in the simulation by transient structural state of the rollers, a maximum total deformation value of 0.07393 mm and a maximum von Mises stress of 15.86 MPa were obtained.  that compared with the creep deformation of 0.175 mm and the creep strength of 250 MPa of the ASTM A36 steel used for its manufacture, no failure occurs due to breakage.