Influence of local structural damage in multilayered thick plate material on the stress distribution

1998 ◽  
Vol 34 (9) ◽  
pp. 873-877
Author(s):  
S. D. Akbarov ◽  
N. Yahnioglu
Keyword(s):  
Stress Distribution ◽  
Structural Damage ◽  
Thick Plate ◽  
Plate Material

Stresses in a Thick Plate With Axially Symmetric Loading

1965 ◽  
Vol 32 (2) ◽  
pp. 458-459 ◽  
Author(s):  
T. J. Lardner
Keyword(s):  
Stress Distribution ◽  
Normal Stress ◽  
Numerical Integration ◽  
Elastic Plate ◽  
Thick Plate ◽  
Axially Symmetric ◽  
Pressure Loading ◽  
Normal Stress Distribution ◽  
Symmetric Loading

The problem of the thick elastic plate with a symmetric circular pressure loading is considered. The normal stress distribution on the midplane and for two positions off the midplane is obtained by a numerical integration of the solutions. A comparison of the stress distribution on the midplane is made with previous results.

Influence of Preparing of Specimen on Internal Stress Measurement of Aluminum Alloy Thick Plate

2010 ◽  
Vol 97-101 ◽  
pp. 2658-2663
Author(s):  
Kai Liao ◽  
Yun Xin Wu ◽  
Hai Gong
Keyword(s):  
Stress Distribution ◽  
Internal Stress ◽  
Surface Stress ◽  
Thick Plate ◽  
Stress Measurement ◽  
Stress Gradient ◽  
Real Surface ◽  
Measurement Results ◽  
Layer Removal Method ◽  
Internal Stress Measurement

The cut, a main preparing means of specimen, will cause a difference in stress distribution between thick plate and the specimen, so this article focuses on the topic of evaluating impact of the cut on stress measurement results. Firstly, the real surface stress distribution of the plate and specimen were determined by X-ray diffraction (XRD) and FEM. Secondly, according to the specimen dimension and machining procedure, the influence of the cut on internal stress measurement is obtained and compared with the FEM results. The conclusions are as follows: (1) the normal stress of cut plane steeply decreases and the stress gradient descends along with distance away from the cut. The range of distance is approximately one-thickness of specimen. (2) In order to obtain stable and reliable results, the plane size of specimen is taken three times larger than the thickness. (3) The milling processing of layer removal method (LRM) can change the surface stress state of specimen, but the machining effects on residual stresses can be removed by properly choosing milling parameters.

Stress Distribution of Aluminum Alloy Thick-Plate under Abnormal Pre-Stretching

2012 ◽  
Vol 204-208 ◽  
pp. 4594-4597
Author(s):  
Kai Liao ◽  
Yun Xin Wu
Keyword(s):  
Aluminum Alloy ◽  
Stress Distribution ◽  
Thick Plate ◽  
Negative Effects ◽  
Thick Plates

Abnormal pre-stretching of aluminum alloy thick-plate is simulated by using Marc FEM software to obtain the stress distribution of the plate under non-uniform clamping condition and material macroscopic deficiency. By analyzing the distribution contours, stress distributing characteristics of the pre-stretched thick-plate and their effects to rolling yield of thick plates under several typical cases are classified and summarized. Moreover, solving measures and advices are presented to reduce the negative effects.

Piezoelectric Based Lamb Waves Generation and Propagation in Orthotropic CFRP Plates: II. Influence of Interfacial Stress Distribution

2019 ◽  
Vol 962 ◽  
pp. 227-235 ◽  
Author(s):  
Maria Shevtsova ◽  
Evgenia Kirillova ◽  
Eugeny Rozhkov ◽  
Valery Chebanenko ◽  
Sergey Shevtsov ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Plate Thickness ◽  
Wave Generation ◽  
Interfacial Stress ◽  
Fe Model ◽  
Damping Properties ◽  
Plate Material ◽  
Structural Anisotropy ◽  
Pzt Actuator ◽  
Cfrp Plate

This paper investigates the Lamb wave generation by the surface bonded circular piezoelectric (PZT) actuator and wave propagation within the orthotropic Carbon Fiber Reinforced Plastic (CFRP) plate considering the anisotropy of the elastic and damping properties of the materials; existence of the adhesive layer; and dependence of the interfacial stress distribution on the surface between host plate and actuator, on the anisotropy of the plate material, and on the excited frequency, wavelength and plate thickness. This part of our investigation includes FE based study of the shear stress distribution on the interface between circular PZT actuator and surface of orthotropic CFRP plate, and its dependence on the excited wavelength and plate thickness. The anisotropic elastic and damping properties of the plate material, which are used in the implemented finite element (FE) model, have been preliminary determined in the first part of our investigation. We compare the behavior of the wave generation, propagation and attenuation that are studied using this model with the similar dependencies obtained at the simulation of the non-dissipating plate excited by the periodical radially oriented force, which is distributed along the circumference bounding the actuator, i.e. 3D pin-force excitation case. The proposed results can be used at the design of SHM for the composite structures with the structural anisotropy and damping, and at making a reasonable choice of the frequency, type, dimensions and optimum placement of the actuators and sensors.

IDENTIFICATION OF IMPACT LOCATION IN A PLATE BASED ON ELASTODYNAMICS AND HIGHER ORDER TIME FREQUENCY METHOD

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1331-1336
Author(s):  
S. K. LEE ◽  
S. J. KIM
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Group Velocity ◽  
Structural Damage ◽  
Nuclear Power ◽  
Thick Plate ◽  
Accurate Estimation ◽  
Frequency Method ◽  
Time Frequency ◽  
The Impact

In a nuclear power plant, impact force due to loose part is related to the structural damage in the plant. In general, the steam generator of the nuclear power plant is structured by thick plate. The paper presents a novel approach to locate an impact load in a thick plate. The approach is based on the analysis of the acoustic waveforms measured by a sensor array located on the plate surface. For accurate estimation of the location of the impact source, the time differences in the arrival times of the waves at the sensors and their propagation velocities are determined. The dispersion curves for multi modes of Lamb wave are calculated by using exact plate theory and SDPT. It is difficult to measure directly the group velocity for Lamb mode of acoustic waveform in the thick plate because they are dispersive wave. However, most of the energy in the wave is carried by the flexural waves (A0 mode), the group velocity of this mode is extracted using the CHOTF technique for estimating the impact source location. The estimates are shown to be in excellent agreement with the actual locations and it is applied to the damage analysis due to the loose part in a nuclear power plant.

Research of Micromechanism on Residual Stress in Aluminum Alloy Thick Plate

2010 ◽  
Vol 146-147 ◽  
pp. 233-237
Author(s):  
Kai Liao ◽  
Xin Xing Jing ◽  
Ya Zhou ◽  
De Qiang Wei
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Aluminum Alloy ◽  
Stress Distribution ◽  
Surface Stress ◽  
Thick Plate ◽  
Inhomogeneous Distribution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Location Area

The research of micromechanism of stress evolvement is presented by analyzing fluctuation and change of surface stress in aluminum alloy thick plate with X-ray diffraction(XRD). From the micro view, a model of “rotation looping and shearing grain” was proposed to analyze and discuss the inhomogeneous distribution of micro-stress in location area, due to inhomogeneity of organization in material. The results present that the inhomogeneity of plastic deformation is direct cause lead to residual stress in plate, and complication of micro-stress distribution results from non-uniformity of organization.

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