Investigation of Timber Members at the Marasyk Station in Prague by Non-Destructive Methods

2013 ◽  
Vol 778 ◽  
pp. 243-249 ◽  
Author(s):  
Hana Hasnikova ◽  
Petr Kuklík
Keyword(s):  
Mechanical Characteristics ◽  
Ultrasonic Waves ◽  
Material Strength ◽  
Structural Members ◽  
Railway Station ◽  
Railway Stations ◽  
Material Quality ◽  
National Heritage ◽  
Non Destructive ◽  
Destructive Methods

The Masaryk Railway Station is the oldest still working terminal railway station in Europe. It was built in 1845 and the buildings belonged to the most splendid railway stations in that time. During the long life the part of Masaryk Station burned, it was also damaged while World Wars and finally large reconstruction started last year. The buildings have a high historical value, so the specialists from National Heritage Institute wanted all the original structural members to be preserved. The structure was constructed from two wooden species spruce and fir. Selected timber elements were tested by various non-destructive methods to assess their health. Pilodyn, a device with iron stick can assess a material quality using correlation between depth of stick indentation and material strength. Sylvatest device operates with ultrasonic waves and can determine dynamic modulus of elasticity as one of the mechanical characteristics. Dynamoe device uses an acoustic wave to assess the material quality. The aim of the paper is to present the procedure of timber testing and to discuss measured results.

scholarly journals Agricultural machine parts quality control by dynamic non-destructive methods

2018 ◽  
Vol 226 ◽  
pp. 04034 ◽  
Author(s):  
Alexey N. Beskopylny ◽  
Viktor B. Rykov ◽  
Elena M. Zubrilina ◽  
Andrey D. Chistyakov
Keyword(s):  
Quality Control ◽  
Wear Resistance ◽  
Manufacturing Process ◽  
Mechanical Characteristics ◽  
Point Of View ◽  
Agricultural Machinery ◽  
Machine Parts ◽  
Non Destructive ◽  
Destructive Methods

The problem of quality control of agricultural machinery parts by means of dynamic non-destructive methods of impact indentation of conical shape indenters is considered. Quality of the crucial parts is considered from the point of view of a set of mechanical characteristics that determine the strength, hardness, wear resistance and deformability. These characteristics must be known and be able to control on all the details promptly and accurately both in the manufacturing process and in operation. The mechanical characteristics of metals are stochastic in nature. For this purpose, an impact indentation device was developed, and the method based on probabilistic laws of dispersion of mechanical characteristics is obtained.

scholarly journals THE ANALYSIS OF METHODOLOGIES FOR TESTING COMPRESSIVE STRENGTH IN MASONRY MORTAR JOINTS / MŪRO SKIEDINIO GULSČIOJOJE SIŪLĖJE GNIUŽDOMOJO STIPRIO TYRIMŲ METODŲ ANALIZĖ

2014 ◽  
Vol 6 (5) ◽  
pp. 514-519 ◽  
Author(s):  
Tomas Šlivinskas
Keyword(s):  
Compressive Strength ◽  
Mechanical Characteristics ◽  
Ultrasonic Waves ◽  
Non Destructive Testing ◽  
Testing Methods ◽  
Destructive Testing ◽  
Advantages And Disadvantages ◽  
Mortar Strength ◽  
Non Destructive ◽  
Masonry Mortar

The article analyzes masonry as composite material and presents the factors that affect the mechanical characteristics of masonry. The article also deals with the most frequently used destructive and non-destructive testing methods for the compressive strength of masonry mortar as well as related advantages and disadvantages. Moreover, the analysis of methods for testing ultrasonic waves has been carried out. The article reveals that for using the methodology of testing a mortar bonded wafer, the compressive strength correlation of masonry mortar is set between the ascertainment of masonry mortar strength using a regular mortar testing methodology (LST EN 1015-11:2004) and the compressive strength of mortar possibly taken from masonry joints. The obtained results of an experimental study on the samples have demonstrated that the strength reduction ratio of masonry mortar depends on the compressive strength of mortar. The value of the ratio is increasing with the descending compressive strength of mortar. Šiame straipsnyje nagrinėjamas mūras kaip kompozitinė medžiaga. Apžvelgiami veiksniai, veikiantys mechanines mūro charakteristikas. Išnagrinėti dažniausiai taikomi mūro skiedinio gniuždomojo stiprio tyrimų metodai, pateikti metodų privalumai ir trūkumai. Straipsnyje, taikant klijuotų skiedinio plokštelių bandymo metodiką, nustatyta mūro skiedinio gniuždomojo stiprio priklausomybė tarp mūro skiedinio stiprio nustatymo pagal įprastinę skiedinio bandymo metodiką ir skiedinio, tikėtina, paimto iš mūro siūlės, gniuždomojo stiprio.

scholarly journals IMPROVEMENT OF THE METHOD OF CONCRETE PHYSICAL AND MECHANICAL PROPERTIES DETERMINATION BY NON-DESTRUCTIVE METHODS

2021 ◽  
pp. 82-89
Author(s):  
V.V. Kolokhov ◽  
Keyword(s):  
Stress Level ◽  
Mechanical Characteristics ◽  
Concrete Strength ◽  
Hydraulic Press ◽  
Structural Element ◽  
Normative Documents ◽  
Non Destructive ◽  
Destructive Methods ◽  
Physical And Mechanical Characteristics

Abstract. To ensure the reliability of existing buildings, facilities and building structures, objective information is required, the receipt of which is mainly associated with the use of non-destructive methods of control. Current normative documents regulate the strength and deformability characteristics of the material, which are used mainly in the design of structures. The normalized value is obtained on the basis of probabilistic and statistical processing and is characterized by some conditional value. Improvement of methods of calculation of constructions connected with the account of elastic-plastic properties of concrete is based on application of the standardized diagrams of work of concrete received on the basis of laboratory experiments. In the real structure due to differences in the composition of laboratory and real concrete, technologies of its manufacture and laying, there may be significant differences from the acquired value "Concrete strength" and "Modulus of elasticity", which was taken to calculate the structure. The above-mentioned influence of the stress level on the readings of the device in determining the strength of concrete by non-destructive testing methods was investigated on concrete samples of six different compositions. Concrete cubes measuring 150×150×150 mm were used to study the stated assumptions. The determination of the strength of concrete samples by the non-destructive method was performed. A sclerometer (Schmidt's Hammer MSH-225) was used to determine, which implements the method of elastic rebound. The determination was performed at different load levels, which was added to the test sample, followed by determination of the strength of concrete on a hydraulic press with a load up to 1250 kN. The analysis of the obtained results shows that the attempt to obtain a generalized calibration curve, which would take into account the change in the stress level in the structure, leads to a decrease in the accuracy of determining the physical and mechanical characteristics of concrete. The presented dependences demonstrate the significance of the influence of the stress level in the structural element on the results of determining the physical and mechanical characteristics of concrete by non-destructive methods. The analysis of these dependences shows the need to modernize non-destructive methods for determining the physical and mechanical characteristics of concrete.

Failure Analysis of Flip-Chip Interconnections Through Acoustic Microscopy

1996 ◽  
Author(s):  
O. Diaz de Leon ◽  
M. Nassirian ◽  
C. Todd ◽  
R. Chowdhury
Keyword(s):  
Failure Analysis ◽  
Large Scale ◽  
Flip Chip ◽  
Ultrasonic Waves ◽  
Acoustic Microscopy ◽  
Acoustic Microscope ◽  
Chip Technology ◽  
Ball Joints ◽  
Non Destructive ◽  
Scanning Acoustic Microscope

Abstract Integration of circuits on semiconductor devices with resulting increase in pin counts is driving the need for improvements in packaging for functionality and reliability. One solution to this demand is the Flip- Chip concept in Ultra Large Scale Integration (ULSI) applications [1]. The flip-chip technology is based on the direct attach principle of die to substrate interconnection.. The absence of bondwires clearly enables packages to become more slim and compact, and also provides higher pin counts and higher-speeds [2]. However, due to its construction, with inherent hidden structures the Flip-Chip technology presents a challenge for non-destructive Failure Analysis (F/A). The scanning acoustic microscope (SAM) has recently emerged as a valuable evaluation tool for this purpose [3]. C-mode scanning acoustic microscope (C-SAM), has the ability to demonstrate non-destructive package analysis while imaging the internal features of this package. Ultrasonic waves are very sensitive, particularly when they encounter density variations at surfaces, e.g. variations such as voids or delaminations similar to air gaps. These two anomalies are common to flip-chips. The primary issue with this package technology is the non-uniformity of the die attach through solder ball joints and epoxy underfill. The ball joints also present defects as open contacts, voids or cracks. In our acoustic microscopy study packages with known defects are considered. It includes C-SCAN analysis giving top views at a particular package interface and a B-SCAN analysis that provides cross-sectional views at a desired point of interest. The cross-section analysis capability gives confidence to the failure analyst in obtaining information from a failing area without physically sectioning the sample and destroying its electrical integrity. Our results presented here prove that appropriate selection of acoustic scanning modes and frequency parameters leads to good reliable correlation between the physical defects in the devices and the information given by the acoustic microscope.

Influence of the applied pressure of the transducer on the propagation speed of the ultrasonic wave in wood

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Edgar V.M. Carrasco ◽  
Rejane C. Alves ◽  
Mônica A. Smits ◽  
Vinnicius D. Pizzol ◽  
Ana Lucia C. Oliveira ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Applied Pressure ◽  
Pressure Gauge ◽  
Eucalyptus Grandis ◽  
Propagation Speed ◽  
Ultrasonic Waves ◽  
Ultrasonic Speed ◽  
Wave Propagation Speed ◽  
Propagation Technique ◽  
Non Destructive

Abstract The non-destructive wave propagation technique is used to estimate the wood’s modulus of elasticity. The propagation speed of ultrasonic waves is influenced by some factors, among them: the type of transducer used in the test, the form of coupling and the sensitivity of the transducers. The objective of the study was to evaluate the influence of the contact pressure of the transducers on the ultrasonic speed. Ninety-eight tests were carried out on specimens of the species Eucalyptus grandis, with dimensions of 120 × 120 × 50 mm. The calibration of the pressure exerted by the transducer was controlled by a pressure gauge using a previously calibrated load cell. The robust statistical analysis allowed to validate the experimental results and to obtain consistent conclusions. The results showed that the wave propagation speed is not influenced by the pressure exerted by the transducer.

Rust creep assessment—A comparison between a destructive method according to ISO 12944 and selected non-destructive methods

2021 ◽  
Vol 157 ◽  
pp. 106293
Author(s):  
Huichao Bi ◽  
Claus Erik Weinell ◽  
Raquel Agudo de Pablo ◽  
Benjamín Santos Varela ◽  
Sergio González Carro ◽  
...  
Keyword(s):  
Non Destructive ◽  
Destructive Methods
Sign in / Sign up

Export Citation Format

Share Document