Main Article Content
IN MANY ENGINEERING APPLICATIONS, THERE ARE SYSTEMS THAT EXHIBIT A SERIES OF COLLISIONS IN A CERTAIN AMOUNT OF TIME, FOR EXAMPLE THE IMPACT OF FLOATING ICE IN SHIPS AND THE RUBBING BETWEEN STATIONARY AND ROTARY PARTS IN TURBOMACHINERY. IN MANY OF THESE SITUATIONS, IT IS OF VITAL IMPORTANCE TO KNOW HOW THE IMPACTS AFFECT THE OVERALL SYSTEM BEHAVIOR FOR THE CORRECT FUNCTIONING OR THE PREDICTION OF FAULTS IN THE SYSTEM. THIS CAN BE DONE BY PROPOSING MODELS THAT CAN REPRESENT THE SYSTEM WHEN IT IS SUBJECTED TO SUDDEN IMPACTS IN ITS OSCILLATION MOVEMENT. HOWEVER, DUE TO THE NONLINEAR AND NON-SMOOTH CHARACTERISTIC OF THE IMPACT PHENOMENON, THE IMPLEMENTATION OF IMPACTS IN MECHANICAL SYSTEMS MAY BE A CHALLENGING TASK. IN THIS MANNER, THIS PAPER AIMS IN PROPOSING A VIBRO-IMPACT MODEL OF TWO ADJACENT PORTAL FRAME STRUCTURES, BEING ONE OF THEM DRIVEN BY AN UNBALANCED DC MOTOR POSITIONED ON TOP OF IT. THE PORTAL FRAMES WERE MODELED AS CONTINUOUS BEAMS BY MEANS OF THE EULER-BERNOULLI BEAM THEORY. IN ORDER TO MODEL THE IMPACT BETWEEN THE STRUCTURES, THREE DIFFERENT MODELS WERE CONSIDERED: USING THE HERTZ THEORY OF ELASTIC BODIES TO MODEL THE CONTACT FORCE USING A NONLINEAR DAMPING; USING A SPRING AND A DAMPER IN PARALLEL, VISCOELASTIC OR SPRING-DASHPOT SYSTEM, TO MODEL THE FORCE; AND CONSIDERING THE IMPACT TO BE INSTANTANEOUS AND USING THE COEFFICIENT OF RESTITUTION TO ADJUST THE VELOCITY AFTER THE CONTACT. TO VALIDATE THE IMPACT MODELS, AN EXPERIMENTAL PROCEDURE WAS PERFORMED AND THE MEASUREMENTS COMPARED WITH THE SIMULATIONS.
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License [CC BY] that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).