Jairo Aparecido Martins

Case study of an evaluation of a Stacker Boom Luffing Pulley by Irwin's model and under BS 7910 guidance

A case study on evaluation of a heavy–duty Stacker Boom Luffing Pulley was presented. Irwins fracture toughness method and the British Standard were used to help in the decision–making process. Using inspection, discontinuities were found at the first look in the cylinder cross–section at the region of welding of the cylinder ends. A more detailed analysis was conducted by ultrasonic mapping, crossing the cylinder transverse thickness and longitudinal to its length. The final decision took into account accurate analysis of the stress σ1 (Principal Stress) from Finite Element Method (FEM) and σref based on British Standard, and comparing the defect real size and the critical crack size calculated by Irwin equation.

Studying 3D clutch segment by Multi physics in heat transfer and solid mechanics, pondering variables Statistically (DOE)

Tridimensional studies of mechanical components are very relevant for design improvements towards the better understanding of stresses magnitude and distribution. When mechanical essay is the matter and thermal variable included, the complexity gets even higher and new interesting scenarios come up. This paper aims to present an axisymmetric 3D clutch in order to understand and ponder mathematically, by novelty Multiphysics (FEM) and statistically (DOE), its design possibilities under external variables (mechanical and thermal). As expected, the identification of main effects and interaction between internal and external variables can significantly contribute favorably to the design of real products, in general, and for this product in particular.

Catastrophic Results for Equipment and Machine Driving Systems when High Impact during Operation Occurs

Energy is vital to machines and equipment basic functioning. On the other hand, it has an ambiguity determined by its detrimental side under other circumstances. This paper aims to present a review of simple laws of physics / mechanics in order to understand some benefits of using such energies (kinetic and potential energies), in order to process products or generating movement (mechanical energy). However, also shows its damaging side for driving systems, where such energies may generate catastrophes, usually due to high impacts. This last, which destroys complete or partial systems due to the absence of any robust / preventive protection. There is a safety manner (solution) to protect the systems, described along the text.