scholarly journals Research on the Parameters Influencing the Numerical Analysis of the Fatigue Behaviour of a Forklift-ARM

2021 ◽  
Vol 10 (1) ◽  
pp. 1-10
Author(s):  
Virgil Florescu ◽  
Ștefan Mocanu ◽  
Ancuța Neagu ◽  
Cristina Sescu-Gal

Abstract Estimating the remaining service life of a forklift for an objective reference is not only a requirement of the applicable legislation but also represents a challenge for specialized technical staff. It is well known that the first fatigue failure element of a forklift is its fork. A simulation using the SolidWorks suite and its result is presented in this article. It allows the identification of critical areas of fatigue failure. Based on the design of the subassembly and the loading scheme of the original product, the model under analysis with finite element was made on a 1: 1 scale. The filet areas also required a comparative analysis of the results obtained depending on the choice of mesh and discretization element. Starting from the mechanical properties of the material as well as the association with the characteristic fatigue yield curves (Wohler), a method for estimating the remaining service life of the structure is proposed. The aspect related to obtaining exact results without an excessive consumption of computing resources was also taken into account.

2021 ◽  
Author(s):  
Bohumil Culek ◽  
Eva Schmidová ◽  
Petr Tomek ◽  
Petr Vnenk ◽  
Marek Pětioký

<p>The reliability of the railway superstructure depends, among other things, on the actual fastening of the rail to the sleepers. This structure is extremely dynamically loaded. In the paper, the attention is paid to the flexible Vossloh W14 fastening system with the use of SKL14 tension clamps. These clamps are often damaged by fatigue failures, especially in curves of small radii (R &lt; 400 m). Within the research, fracture areas were identified and a fractographic analysis was performed. The analysis proved fatigue failure and, therefore, an estimation of the service life of the clamps was made. The evaluation was focused on a selected area of railway track where the fatigue-damaged clamps were found. The strain gauges were placed directly on the clamps at critical points and the obtained values were confronted with the experimentally obtained fatigue curve. Based on the presented findings, the service life of the clamps in the selected track was identified.</p>


1997 ◽  
Vol 503 ◽  
Author(s):  
H. Jiang ◽  
M. K. Davis ◽  
R. K. Eby ◽  
P. Arsenovic

ABSTRACTPhysical properties and structural parameters have been measured for ropes of nylon 6 as a function of the number of use operations. The fractional content of the α crystal form, sound velocity, birefringence, tensile strength and length all increase systematically and significantly with increasing the number of use operations. The fractional content of the γ crystal form and fiber diameter decrease with use. These trends indicate that the measurement of such properties and structural parameters, especially the length, provide a possible basis for establishing a reliable, rapid, and convenient nondestructive characterization method to predict the remaining service life of nylon 6 ropes.


Author(s):  
J. H. Shepherd ◽  
K. Legerlotz ◽  
T. Demirci ◽  
C. Klemt ◽  
G. P. Riley ◽  
...  

Overuse tendinopathies are often considered to be the result of repeated microstrain below the failure threshold, analogous to the fatigue failure of materials under repeated loading [1, 2]. Investigation of tendon overuse in vitro is thus of potential benefit towards characterizing the progression of damage.


2009 ◽  
Vol 167 (2) ◽  
pp. 1-9
Author(s):  
Shinsuke Miki ◽  
Hiroshi Okazawa ◽  
Taketoshi Hasegawa ◽  
Sei Tsunoda ◽  
Hiroshi Inujima

Volume 3 ◽  
2004 ◽  
Author(s):  
L. Han ◽  
K. Young ◽  
R. Hewitt ◽  
A. Chrysanthou ◽  
J. M. O’Sullivan

Self-piercing riveting, as an alternative joining method to spot-welding, has attracted considerable interest from the automotive industry and has been widely used in aluminium intensive vehicles. One of the important factors that need to be considered is the effect of cyclic loading in service, leading to possible fatigue failure. The previous work reported in the public domain on the behaviour of self-piercing rivets has mainly focused on static tests. The work which is reported in this paper is concerned with the fatigue behaviour of single-rivet joints, joining two 2mm 5754 aluminium alloy sheets. The investigation also examined the effect of interfacial conditions on the fatigue behaviour. A number of fatigue failure mechanisms were observed based on rivet fracture, sheet fracture and combinations of these. The investigation has shown that they were dependent on the applied load and the sheet surface condition. Three-parameter Weibull analysis, using Reliasoft Weibull ++5.0 software, was conducted to analyse the experimental results. The analysis enabled the prediction of early-type failure (infant mortality failure) and wear-out failure patterns depending on the condition of the self-piercing riveted joints and the alloy sheet surface.


2020 ◽  
Vol 5 (9) ◽  
pp. 77
Author(s):  
Cláudia Ferreira ◽  
Ana Silva ◽  
Jorge de Brito ◽  
Ilídio S. Dias ◽  
Inês Flores-Colen

Existing maintenance policies have several limitations, mainly due to the lack of knowledge regarding the durability and performance of buildings. Usually, the maintenance policies are insufficiently accurate, neglecting the risk of failure over time and the global costs associated with repairs. In this study, a condition-based maintenance model, based on Petri nets, is proposed to evaluate the impact of three maintenance strategies of ceramic claddings in pitched roofs (CCPR): MS1—only total replacement; MS2—composed of total replacement and minor intervention and MS3—composed of total replacement, minor intervention and cleaning operations. In this study, 146 CCPR were inspected in situ, with a total area of 43,991.6 m2. The remaining service life of the CCPR; the global costs over the claddings’ lifetime (considering inspection, maintenance, replacement and disposal costs); the claddings’ degradation condition and the number of replacements during the time horizon are used to evaluate the performance of the different maintenance strategies through a simplified multi-criteria analysis. The results show that the gains in performance, in terms of expected service life and durability, of the consideration of preventive maintenance actions (minor interventions or cleaning operations) outweigh the increase of the operation costs.


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