Nondestructive Testing Of Mechanical Properties Research Articles

Non-destructive testing of mechanical properties of solid wood panel based on partial least squares structural equation modeling transfer method

Calibration transfer between near infrared (NIR) spectrometers is a subtle issue in the chemometrics and process industry. Similar instruments may generate strongly different spectral responses, and regression models developed on a first NIR system can rarely be used with spectra collected by a second apparatus. In this work, two novel methods based on Structural Equation Modeling (SEM), called Enhanced Feature Extraction Approaches for factor analysis (EFEA-FA) and Enhanced Feature Extraction Approaches for spectral space transformation (EFEA-SST), were proposed to perform calibration transfer between NIR spectrometers. They were applied to a NIR nondestructive testing model for solid wood panels mechanical properties. Four different standardization algorithms were evaluated for transferring solid wood panels quality databases between a portable NIRS (InGaAs)-array spectrometer (NIRquest512) and a HSI Camera (SPECIM FX17). The results showed that EFEA-SST yielded the best model evaluation metrics (R2 and Root Mean Square Error of Prediction (RMSEP)) values for tensile strength (RMSEP=11.309, R2=0.865) parameters, while EFEA-FA gave the best fit for flexural strength (RMSEP=10.653, R2=0. 912). These results suggest the potential of two novel quality parameters prediction methods based on spectral databases transferred between diverse NIRS spectrometers.

Nondestructive Testing of Mechanical Properties of Bamboo–Wood Composite Container Floor by Image Processing

The bamboo–wood composite container floor (BWCCF) has been wildly utilized in transportation in recent years. However, most of the common approaches of mechanics detection are conducted in a time-consuming and resource wasting way. Therefore, this paper aims to provide a frugal and highly efficient method to predict the short-span shear stress, the modulus of rupture (MOR) and the modulus of elasticity (MOE) of the BWCCF. Artificial neural network (ANN) models were developed and support vector machine (SVM) models were constructed for comparative study by taking the characteristic parameters of image processing as input and the mechanical properties as output. The results show that the SVM models can output better values than the ANN models. In a prediction of the three mechanical properties by SVMs, the correlation coefficients (R) were determined as 0.899, 0.926, and 0.949, and the mean absolute percentage errors (MAPE) were obtained, 6.983%, 5.873%, and 4.474%, respectively. The performance measures show the strong generalization of the SVM models. The discoveries in this work provide new perspectives on the study of mechanical properties of the BWCCF combining machine learning and image processing.

Safe mechanical joining processes by digital manufacturing supervision in steel coil productions

Mechanical joining processes, in particular joining by forming like self-pierce riveting or clinching, require homogenous material characteristics for reliable joint properties. Joining processes in production are called safe, when the estimated properties for each manufactured joint, e.g. strength, remain in predefined narrow boundaries. Thus, an automated process monitoring is possible. A key reliability factor in automated production are varying joining materials properties. In case of steel, the knowledge of mutually dependent manufacturing steps at the coil build-up are crucial: First, milling conditions, such as dressing grade, predetermine the mechanical strength and fracture strain of the later joint. Second, the structure of corrosion protection layer by electrolytic or hot-dip galvanizing combined with forming and corrosion protection lubricants define the gliding abilities at later joining processes. It was found that a high dependency exists between solidification behaviour as well as surface friction level of the joining material and the stability of the joining process and the load capacity of the joint. To achieve safe mechanical joining results, these mentioned material properties must be guaranteed precisely by production monitoring techniques at the coil manufacturing. These include among others, methods for the non-destructive testing of mechanical properties at different coil areas, as well as systems for monitoring surface conditions and layers. As the material properties are build up over several production steps, production data are digitally collected today, analysed under quality aspects and if necessary corrective measurements are set online in the production.

Application of Magnetic Noise Method to Control the Mechanical Anisotropy of Ferromagnetic Materials

Presence of anisotropy of the ferromagnetic materials' properties determines the need for its research and control, since it has a significant impact on the basic physicomechanical characteristics of details, products and constructions. The aim of the work was to experimentally investigate the possibility of using the magnetic noise method for non-destructive testing of mechanical properties of ferromagnetic materials particularly value of the coefficient of normal anisotropy Rn of sheet metal, mechanical stresses under elastic deformation of electrical steel and the anisotropy of the physical and mechanical properties of ferromagnetic materials.Since the mechanical anisotropy is related to the magnetic anisotropy, the magnetic method of the Barkhausen effect (MBE) was used in its study, the informative parameters of which belong to the group of magnetic anisotropy. Comparison of the results of anisotropy evaluation on a set of samples of stamped sheet steel using the MBE with values Rn measured by the manufacturer showed their close match. This revealed the possibility of Rn level evaluation using the MBE. Device for circular rotation of the Barkhausen transducer on the sample surface and device for forming of elastic bending stresses in the sample were constructed. To study the magnetic anisotropy in various materials and the impact of elastic tensile and compressive stresses by bending on it using the MBE.It has been found that the elastic deformation in samples of electrical steel leads to dramatic change of the magnetic noise level and the shape of the circular diagrams, taking into account the sign of the stresses generated in the sample. It was established that as a result of cold rolling in the production process, electrical steel samples have a pronounced texture due to the direction of rolled sheet. The created elastic stresses in the considered range practically do not change the texture (induced crystallographic anisotropy) after the material rolling.The results can be useful for studying, monitoring and testing of anisotropy, crystallographic texture, structural heterogeneity of ferromagnetic materials in the form of sheet metal, sheet steel and coil steel, sheet metal forming and for solving other problems using the magnetic noise method in aboratory and workshop conditions.

Quality control of heat treatment of oil and gas pipes using magnetic structuroscopy

The problem of the development of in-line nondestructive testing of mechanical properties of heat-strengthened oil and gas steel pipes remains topical. In this work, the effect of heat treatment conditions represented by the quenching temperature (in the range of 765–980°C) and cooling rate from the quenching temperature (in the range of 500–720°C, after quenching in water) on the structure, hardness, and magnetic properties (coercive force, residual induction, maximum magnetic permittivity, and saturation magnetization) is studied for the widely used pipe steels of 22KhG2A, 30KhMA, and 32G2 brands. The magnetic parameters are measured both in a closed magnetic circuit and using the attached magnetic devices on model and full-scale samples. A possible application of the coercimetric method as an alternative for the durametric one is shown for continuous underheating testing for quenching and the tempering quality of the pipes made from the steels under study during fabrication.

Non-Destructive Testing of Mechanical Properties of Magnetic Materials Using Barkhausen Noise and B-H Loop Techniques

A magnetic-based nondestructive evaluation (NDE) method, which employs Barkhausen effect and measurement of hysteresis loops, is developed and used to correlate the magnetic and mechanical properties. The NDE test equipment offers the capability to detect small deviations from linearity that occur in the stress-strain curve.

Nondestructive Testing of Mechanical Properties of Pine Laminated Veneer Lumber

Laminated Veneer Lumber (LVL) panels made from pine (Pinus sylvestris L. Var. mongolica Litven.) veneers were tested for mechanical properties and prediction models in this study. Three different nondestructive testing (NDT) methods and the static bending test were conducted on the LVL. The NDT methods included the longitudinal vibration method, longitudinal transmission method and flexural vibration method. The effects of veneer thickness on the dynamic Young’s modulus and the modulus of elasticity (MOE) of pine LVL with vertical load were investigated. There were four variety thickness veneers including 2.2 mm, 2.6 mm, 3.0 mm and 3.4 mm. The results showed that the dynamic Young’s modulus and MOE of LVL diminished with the increase of veneer thickness, there was a strong linearity correlation between each dynamic Young’s modulus and the static MOE, and the prediction models of mechanical properties can be used to predict MOE of pine LVL.

Increasing the reliability of the multiparametric method for nondestructive testing of mechanical properties of articles

It is suggested that the corrected least squares procedure be applied in order to improve the results obtained during nondestructive testing of the service properties of articles by the multiparametric method. The result of the statistical manipulation, which is given in the form of a correlation between the calculated and experimental magnitudes of a tested property, improves the pair correlation in use of a procedure developed earlier [1]. The conditions of the expediency of applying such improvement are studied.

Multiparameter methods in magnetic structuroscopy and nondestructive testing of mechanical properties of steels

Methods of nondestructive testing of the quality of metal in hot-rolled, thermally treated, and other states are considered for the cases when structural changes are diversified, one of such structural transformations having an opposite effect on the sensitivity of a particular characteristic to the accompanying transformation, and when one-parameter inspection according to the coercive force is either inefficient or impossible. The natures of the structural and phase sensitivity of the coercive force, the saturation magnetization, and the magnetic permeability are analyzed. Examples of the practical application of multiparameter magnetic structuroscopy are considered.

Nondestructive Testing of Mechanical Properties of Rolled Steel (Review): 2. Testing of Ductile Properties

The results of the first studies that established a correlation between impact ductility and coercivity are considered in this review. The data of studies on the search for the factors that encourage or inhibit this correlation are analyzed. The methods based on estimation of the coercivity, which ensure increased reliability of nondestructive testing of rolled steel with a tendency toward brittle fracture, are discussed. The experimental data on nondestructive tests of impact ductility carried out using a sharp notch are analyzed.

Nondestructive Testing of Mechanical Properties of Rolled Steel (Review): 1. Tests of Strength and Plastic Properties

This review considers the creation and development of a nondestructive technique based on coercive-force measurements used to determine strength and plastic properties of industrial rolling products made from Russian-produced low-carbon and low-alloy steels. The operating principle for a coercimeter equipped with a field electromagnet is described briefly. Regression lines of mechanical properties versus coercimeter readings are presented for 20Κ- and 09Γ2-steel sheets produced by Nizhni Tagil Iron and Steel Works. Different methods for considering sheet thickness and tube dimensions are discussed.

Modern State of Nondestructive Testing of Mechanical Properties and Stamping Ability of Steel Sheets in a Manufacturing Technological Flow

The modern state of methods and instruments of nondestructive testing of mechanical properties and stamping ability in a manufacturing technological flow is systematized and analyzed. The underlying principles of designing and features of operation of these instruments, as well as their basic advantages and limitations and ways of reducing the effect of interfering factors, are considered.

Study on the possibility of nondestructive testing of mechanical properties of petroleum gauge: Bida, G.V.; Sazhina, E.Yu.; Pochueve, N.D.; Tsar'kova, T.P.; Nesterova, O.V. Defektoskopiya, No. 2, pp. 82–88 (1995)

Study on the possibility of nondestructive testing of mechanical properties of petroleum gauge: Bida, G.V.; Sazhina, E.Yu.; Pochueve, N.D.; Tsar'kova, T.P.; Nesterova, O.V. Defektoskopiya, No. 2, pp. 82–88 (1995)

振動法によるシェル鋳型のヤング率と強度について

This paper describes some fundamental features obtained through application of the technique of measuring the sonic modulus of materials used in the field of ceramics to the nondestructive testing of mechanical properties of Shell Mold; namely, the authors try to find the relation of Young's modulus determined from the fundamental frequencies of prismatic samples to the modulus of rupture and the internal structure of the same samples that depends upon the packing properties of molding sand and physical properties of bonding materials, and considerable correlations are found between these quantities at least under limited conditions.