Failure analysis of four-cylinder diesel engine crankshaft

Abstract

In this article, failure analysis was examined in four-cylinder light-duty truck diesel engine crankshaft. The failure happened in service after 95,000 km of operation by fatigue crack growth which was initiated from a surface defect on the second crankpin from the crankpin-web fillet. For such objective, standard specimens were cut off from the crankshaft and examined to evaluate the mechanical properties. Some hardness and tensile tests were conducted, and spectrometry analysis was used in order to study the chemical composition of the crankshaft material. Also, for considering and evaluating the microstructure, microcracks, fracture surface and the cause of failure, optical microscopy and scanning electron microscopy equipped with energy-dispersive spectrometry were used. The morphology of the fracture surface shows that the failure happened in the second crankpin at the crankpin-web fillet of crankshaft where the stress concentration was the highest.

Study of the Rotary Bending Fatigue Resistance of 30MnB5, 41CrS4 and 30MnVS6 Steels

“…Aliakbari et al [34] state that the majority of combustion engine vehicle axle failures are due to fatigue failures related to bending stresses. Therefore, the evaluation of the fatigue resistance of alternative steels is essential to establish whether the reference steel-30SnB5 (B1)-can be substituted for them.…”

Change of Carrying Shaft Innovative Capacity in The Process of Growth of Fatal Cracks

“…A distinctive feature of fatigue damage (damage) of parts is their lesser suitability for recovery [2][3][4][5][6]. As a rule, parts with fatigue cracks can not be repaired and discarded.…”

Development of a Passive Prosthetic Hand That Restores Finger Movements Made by Additive Manufacturing

“…For assembly and finishing the average time consumed was 3 h. The final weight of the fully assembled device was 263.90 g. The estimated cost of the device is $60.82, which is a low cost compared to the cost of conventional prostheses, with values ranging from $316.30 to $1408.75 [33,34]. In addition, in the global market, there are upper limb prostheses with sophisticated operating systems that cost between $25,000 and $58,000 per unit [25,35,36]. Regarding the weight achieved in the prosthesis (less than 270 g) developed in this project, it is essential for the user in the adaptation process, to have prosthetic devices that have the ability to combine mechanical strength and low weight, being extremely important factors in the rehabilitation process.…”

“…For the development of the simulation finite element model to evaluate the stress concentration on the surface [31,[37][38][39][40], forces of 7.5 N were used in the distal region of the phalanges individually, according to the bibliographic orientation [19,20,23,25,35,36]. Responses to the proposed loads showed maximum stress of 13.45 MPa on the braided line near the proximal phalanges, as shown in Figure 20.…”