Optimizing the Design of Connecting Rod under Static and Fatigue Loading
The main objective of this work is to re-optimize the existing design of connecting rod of universal tractor (U650) by changing some of the design variables. The existing design performs modelling and evaluates critical regions in the connecting rod under fatigue loading. In the present work, the model is developed, analyzed and designed using CATIA 19, PRO-E and ANSYS workbench v12. Optimization of connecting rod is done under same boundary and loading conditions for variation in the few stress and fatigue parameters i.e. stresses, weight, life, damage, bi-axiality indication and safety factor. The allowable numbers of cycles under fully reversed fatigue loading are increased and assumed up to a maximum limit of 10 cycles. Stress concentration coefficient is varied to obtain the maximum cycles condition. The critical regions under both static and fatigue analysis are identified and improved. The connecting rod is modelled and optimized for the reduced weight, improved life and manufacturability. The results obtained from performed analysis can be used to modify the design of existing connecting rod, so that better performance i.e. reduced inertia, fatigue life and manufacturability can be obtained under varying static and fatigue conditions.
Optimization of connecting rod of MF-285 tractor
MF-285 tractor has devoted the highest production level in Iran among the other tractors. Engine internal components malfunction of this tractor is high. Above reasons necessitate proper optimization of these components. In this study, detailed load analysis under service loading conditions was performed for connecting rod of this tractor (using the Mathematica software), followed by finite element analysis (FEA) to capture stresses and fatigue cycle (using ANSYS software) and at the end proper proposals were offered for optimizing this component. The results showed that increasing the diameter of pin end, decreasing the diameter of rod, optimization of reciprocating mass and lessen friction between piston pin and connecting rod bush are proper methods to optimize the model for better resistance under hard loads.
Scaffolds Containing Spirulina sp. LEB 18 Biomass: Development, Characterization and Evaluation of In Vitro Biodegradation.
Polymer nanofibers are nanomaterials that can be used as scaffolds in tissue engineering. The objective of this study was to develop, characterize and evaluate the in vitro degradation of a biomaterial consisting of nanofibers produced from biodegradable and biocompatible polymers with potential applications as a scaffold for tissue regeneration and containing Spirulina sp. LEB 18 biomass as the bioactive compound. The polymers used were poly(hydroxybutyrate-co-hydroxyvalerate) and polycaprolactone. The polymeric solutions exhibited sufficiently high viscosity to produce uniform nanofibers with diameters between 335 and 617 nm. The applied conditions were as follows: a voltage of 25 kV, a distance from the capillary to the collector of 120 mm, a capillary diameter of 0.80 mm, and 12% polycaprolactone and a blend of 5% polycaprolactone and 10% poly(hydroxybutyrate-co-hydroxyvalerate). The biomass was incorporated into the nanofibers at a concentration of 3%, and the incorporation was confirmed using confocal microscopy. The nanofibers were characterized using differential scanning calorimetry and thermogravimetric analysis, which showed that the addition of biomass did not alter the thermal properties of the biomaterial. The addition of biomass improved the tensile strength and elongation of the scaffolds compared with those produced with polymers alone. A biodegradation assay showed enzymatic action toward the biomaterial, simulating the behavior of natural tissue. Based on the analysis, it was concluded that the scaffolds that were produced have the potential to be applied in the field of tissue regeneration as biomaterials with pharmacological properties.