scholarly journals Non-destructive testing of welded fatigue specimens

2020 ◽  
Vol 318 ◽  
pp. 01033
Author(s):  
Sofia Papanikolaou ◽  
Dimitrios Fasnakis ◽  
Andreas Maropoulos ◽  
Dimitrios Giagopoulos ◽  
Stergios Maropoulos ◽  
...  
Keyword(s):  
Fatigue Testing ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Metallographic Examination ◽  
Welding Method ◽  
Steel Material ◽  
The One ◽  
Non Destructive ◽  
Wheel Material ◽  
Ultrasound Testing

Non-destructive tests were conducted on welded fatigue specimens prepared using the same steel material and welding method as the one used in the manufacture and repair procedures of a KRUPP SchRs 600 bucket wheel excavator to reveal any defects present. The chemical composition, the mechanical properties, tendency to cracks and the microstructure of the bucket wheel material were determined using appropriate tests. The initiation of cracks and their subsequent growth during fatigue testing of the welded specimens was studied using ultrasound testing (UT) and a metallographic examination in order to investigate the causes of failure during service and predict fatigue life of the bucket wheel welded parts. It was found that the welding method used produces welds with numerous discontinuities that can only be detected using ultrasound techniques.

INVESTIGATION OF THERMAL DIFFUSIVITY–MICROHARDNESS CORRELATION EXTENDED TO SURFACE-NITRURED STEEL USING BOUBAKER POLYNOMIALS EXPANSION

2008 ◽  
Vol 22 (29) ◽  
pp. 2893-2907 ◽  
Author(s):  
TAHER GHRIB ◽  
KAREM BOUBAKER ◽  
MAHMOUD BOUHAFS
Keyword(s):  
Thermal Diffusivity ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Carburized Steel ◽  
Steel Material ◽  
Boubaker Polynomials ◽  
Surface Performance ◽  
Special Concern ◽  
Quenched Steel ◽  
Non Destructive

This study sums up the authors recent works1–6 on steel regarding non-destructive testing and evaluation achieved between 2000 and 2008. The main related items are the establishment of a polynomial correlation4 between the thermal diffusivity and the Vickers' hardness HV using the recently established Boubaker polynomial expansion. This correlation is undoubtedly an efficient guide to set an NDT protocol to investigate steel-strengthened surface performance. Special attention is given to carburized steel material,6 as the existence of any appropriated NDT photothermal technique is demonstrated2,5,6 to be unavoidably subjected to some restrictive conditions. The perspectives of the new features of this recent technique are discussed, with special concern with differently treated material like nitrured and nitrocarburized quenched steel.

Bending Tests and Simulations of GLT Beams

2014 ◽  
Vol 611 ◽  
pp. 54-59
Author(s):  
Lenka Melzerová ◽  
Michal Šejnoha ◽  
Pavel Klapálek
Keyword(s):  
Modulus Of Elasticity ◽  
Stochastic Simulations ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Four Point Bending ◽  
Research Activities ◽  
The One ◽  
Probability Density Distributions ◽  
Non Destructive ◽  
Timber Beams

The paper reports on two specific research activities devoted on the one hand to detailed finite element simulations of glued timber beams with emphases on random nature of the modulus of elasticity and, on the other hand, to destructive testing of a set four glued timber beams having structural dimensions. While the stochastic simulations were founded on the knowledge of probability density distributions of the modulus of elasticity acquired from non-destructive testing of local moduli from 3600 regularly spaced indentation measurements, the destructive testing of beams in four-point bending aimed at providing information to be used a-posteriori in improving the original predictions in the framework of Bayesian statistics. In this regard the non-destructive testing together with stochastic simulations of beam deflections is assumed to provide prior information to be updated in the second Bayesian step. This, however, will be discussed elsewhere so that only necessary prerequisites are mentioned here.

Influence of Moisture of Light-Weight Concrete Containing Lightweight Expanded Clay Aggregate on Test Results Obtained by Means of Impact Hammer

2013 ◽  
Vol 753-755 ◽  
pp. 663-667
Author(s):  
Jiří Brožovský
Keyword(s):  
Lightweight Aggregate ◽  
Normal Weight ◽  
Light Weight ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Normal Weight Concrete ◽  
Light Weight Concrete ◽  
Rebound Number ◽  
The One ◽  
Non Destructive

Properties of light-weight concrete congaing lightweight expanded clay aggregate differ from the ones of normal-weight concrete containing natural normal-weight aggregate. Particularly, when compared with natural normal-weight aggregate, these differences are due to lightweight aggregate being characterized by significantly lower strength and bulk weight as well as higher absorptivity. Properties of expanded clay lightweight aggregate influence the ones of light-weight concrete, too. Parameters obtained by means of Schmidt impact hammer non-destructive testing are influenced by series of factors, among others also concrete moisture. Moisture of light-weight concrete containing lightweight aggregate influences rebound number of Schmidt impact hammer. As to Schmidt impact hammer type N (2.25 Nm impact energy), rebound number on dry concrete exceeds the one on waterlogged concrete by 21 %. Correction coefficients for rebound number correction were defined taking into account moisture of light-weight concrete under testing.

scholarly journals Nonlinear spectral correction of the pulse GPR signals

2018 ◽  
Keyword(s):  
Thickness Measurement ◽  
Point Of View ◽  
Building Structures ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Electromagnetic Pulses ◽  
Industrial Structures ◽  
The One ◽  
Ground Penetrating ◽  
Non Destructive

Background: The problems of non-destructive testing of industrial structures and transport structures are relevant from the point of view of increasing the efficiency of their control systems and saving financial resources and materials. The relevance of scientific research in the field of remote sensing and methods for solving inverse problems is also associated with the prospects for the formulation and solution of biomedicine problems associated with computer technology. Objectives of the work is to study the possibilities of virtual adjustment of the properties of probing and reflected signals to increase the reliability of processing results and increase the accuracy of restoration of the properties of objects when solving thickness measurement problems. Materials and methods: The basis of the proposed approach is the correction of the amplitudes of pulse signals in order to increase the accuracy of the values ​​obtained as a result of processing by introducing a normalizing factor into the processing algorithm, the value of which would be a function obtained as a result of GPR calibration procedures. Another way to increase the reliability of the data processing procedure may be by computer correction of the waveform to approximate its shape to the shape of an idealized model pulse. Results: As a result of theoretical analysis, methods and algorithms for implementing the procedure for improving the processing of sets of primary sensing data obtained using pulsed georadars were proposed. Conclusion: The analysis of the methods for processing and adjusting the characteristics of pulsed ground-penetrating radar signals made it possible on the one hand to better understand the physical basis for the interaction of electromagnetic pulses with plane-layered media. On the other hand, practical methods of improving the quality control of various engineering and transport structures, as well as building structures, are proposed.

Correlation between Crack Growth Rate and Magnetic Memory Signal of X45 Steel

2007 ◽  
Vol 353-358 ◽  
pp. 2293-2296 ◽  
Author(s):  
Hai Yan Xing ◽  
Ri Xin Wang ◽  
Min Qiang Xu ◽  
Jia Zhong Zhang
Keyword(s):  
Growth Rate ◽  
Crack Growth Rate ◽  
Crack Growth ◽  
Fatigue Testing ◽  
Magnetic Memory ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Three Point Bending ◽  
Growth Evaluation ◽  
Non Destructive

Crack growth rate, as an important parameter, is widely applied in crack growth evaluation and fatigue life prediction. The objective of this paper is to study crack growth rate with the metal magnetic memory (MMM) technology which is a non-destructive testing method newly developed. The correlation between crack growth rate da / dN and magnetic memory signal Hp(y) is investigated through three-point bending fatigue testing. Samples of steel X45, with different heat treatments, quenching and thermal refining, are tested in HYG fatigue machinery. The correlation curves of da / dN ~ Hp(y) are built and the characteristics of magnetic memory signal are given. The influence of heat treatment on Hp(y) is also analyzed. The crack growth rate model of X45 based on MMM signal is presented and verified.

Non-Destructive Testing of Steel Wire Rope Transmission Area to Rope End by Magnetic Flux Leakage

2014 ◽  
Vol 683 ◽  
pp. 39-44 ◽  
Author(s):  
Pavel Peterka ◽  
Jozef Krešák ◽  
Stanislav Kropuch ◽  
Andrea Bérešová ◽  
Dušan Mitrík
Keyword(s):  
Magnetic Flux ◽  
Steel Wire ◽  
The State ◽  
Point Of View ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Steel Material ◽  
Transmission Area ◽  
Non Destructive ◽  
Flux Leakage

At present the need of nondestructive testing of rope bridges state appears often. Modern maintenance trends using non-destructive checking allow to detect the state of these materials in service without breaking their integrity. From the point of view of so far used non-destructive testing methods the area of cable end is not accessible. The magnetic properties research of these materials and the subsequent design of new structures for scanning elements will enable non-destructive monitoring of the state of the ropes steel material of static constructions, especially their anchoring. The article aims to present the results from tracking of the magnetic flux around the cable end and signal runs from particular designed and investigated scanning elements placed above artificial defects created closely to the cable end.

scholarly journals Acoustic Measurements to Proof High-Strength Structures and Joints

2010 ◽  
Vol 137 ◽  
pp. 451-456
Author(s):  
A. Lohrengel ◽  
Daniel Thoden ◽  
Günter Schäfer
Keyword(s):  
High Strength ◽  
Preliminary Test ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Promising Tool ◽  
Innovative Materials ◽  
Material Sciences ◽  
Reduce Energy Consumption ◽  
The One ◽  
Non Destructive

Due to increased product requirements, usual conditions for materials cannot be applied anymore. To reduce energy consumption, lightweight constructions are demanded but they cannot stand necessary mechanical stress. Therefore, local reinforced elements are applied for instance. According to actual research in material sciences, it is prerequisite to verify the position of this strengthening. Various physical principles can be used for non-destructive testing of this effect. In this article, an approach based on acoustic signals is presented. On the one hand a strategy could be to do comparative studies between nominal and sample and on the other to predetermine the place just by acoustic parameters like eigenmodes. In preliminary test, vibration characteristics of these innovative materials (e.g. bake-hardening plate and sandwich structure) are determined and reveal capabilities for acoustic methodologies. So, this approach could be a promising tool to localize reinforced elements.

Sign in / Sign up

Export Citation Format

Share Document