scholarly journals Drying-Induced Strain-Stress and Deformation of Thin Ceramic Plate

2020 ◽  
Vol 4 (1) ◽  
pp. 9 ◽  
Author(s):  
Yoshinori Itaya ◽  
Hiroya Hanai ◽  
Nobusuke Kobayashi ◽  
Tsuguhiko Nakagawa
Keyword(s):  
Tensile Stress ◽  
Thin Plate ◽  
Moisture Transfer ◽  
Electronic Materials ◽  
Maximum Principal Stress ◽  
Thin Plates ◽  
Ceramic Plate ◽  
Air Stream ◽  
Strain Stress ◽  
Drying Conditions

Ceramic thin plates are applied to several industrial purposes including electronic materials and sensors. Drying-induced shrinkage and strain-stress formation of a ceramic thin plate were studied experimentally and theoretically. A kaolin thin plate molded into 10 mm × 30 mm × 1 mm was dried in a hot air stream, and the drying characteristics and deformation were examined. Modeling was also performed to predict the behavior. Heat and moisture transfer conservation equations and constitution equations based on viscoelastic strain-stress were simultaneously solved by a finite element method. A test piece of the thin plate was warped when only one side of the plate was dried, while it was almost flat when both sides were dried. The behaviors of drying and deformation were predicted with a reasonable agreement by the modeling. Parametric analyses by the modeling revealed that the drying conditions with faster drying rate in the beginning period resulted in formation of greater maximum principal stress, and drying on only one side of the plate induced stronger tensile stress in falling rate period than that with both sides drying. The larger thickness of the plate influenced the formation of significantly greater tensile stress but affected maximum compressive stress only a little.

Research on Vibration Control of Thin Plate Based on Pre-Stressing

2018 ◽  
Author(s):  
Cheng Zhang ◽  
Jian-run Zhang ◽  
Xi Lu
Keyword(s):  
Differential Equation ◽  
Stress Distribution ◽  
Tensile Stress ◽  
Vibration Control ◽  
Thin Plate ◽  
Natural Frequencies ◽  
Control Method ◽  
Dynamic Stiffness ◽  
Thin Plates ◽  
Shape Functions

The weak dynamic stiffness of thin plate is one of the important factors that limit the use of thin plate. Improving the dynamic stiffness of thin plate is one of the effective methods for the vibration control of thin plate. In this paper, the influence of pre-stress on the vibration characteristics of thin plate is studied. A vibration control method of thin plate based on pre-stress is proposed. The vibration differential equation of quadrate thin plate under pre-stressing is established. Using the Galerkin principle, the natural frequencies corresponding to the shape functions of the quadrate thin plates under pre-stressing in different distribution forms are obtained. By comparison, it is found that pre-stressing on the thin plate can change the dynamic stiffness of thin plate. In particular, tensile stress can increase the dynamic stiffness of thin plate while compressive stress can reduce the dynamic stiffness of the thin plate. The greater the pre-stress, the more obvious the effect. In the end, the requirements of the pre-stress distribution which can improve the dynamic stiffness of thin plate effectively are derived.

Study of Effect on Tensile Stress Test from Distortion of Fibre Laser Welded Ti6Al4V Using FEA

2011 ◽  
Vol 314-316 ◽  
pp. 1889-1894
Author(s):  
Yu Fan ◽  
Philip Shipway ◽  
Geoff Tansley ◽  
Zheng Chen
Keyword(s):  
Tensile Stress ◽  
Laser Welding ◽  
Tensile Test ◽  
Thin Plate ◽  
Stress Level ◽  
Continuous Wave ◽  
Stress Test ◽  
Welding Distortion ◽  
Fibre Laser

Distortion is one type of defect in the weld, which is troublesome for some reasons, especially in thin plate welding. Distortion was found in fibre laser welding processing for 0.7mm thickness Ti6Al4V plate. The purpose of this paper is to understand and evaluate the effect of distortion on stress level by FEA and tensile test. A group of 0.7mm Ti6Al4V plates welded using continuous wave fibre laser. FEA models were established for fibre laser welded Ti6Al4V in abaqus 6.7.

Effect of Hydrogen on the Fracture Behavior of High-Strength Cr-Mo Steel

2006 ◽  
Vol 512 ◽  
pp. 55-60 ◽  
Author(s):  
Mao Qiu Wang ◽  
Eiji Akiyama ◽  
Kaneaki Tsuzaki
Keyword(s):  
Tensile Stress ◽  
Power Law ◽  
High Strength ◽  
Maximum Tensile Stress ◽  
Maximum Principal Stress ◽  
Slow Strain Rate Test ◽  
Diffusible Hydrogen ◽  
Thermal Desorption Spectrometry ◽  
Stress Concentration Factors ◽  
Peak Value

We examine the hydrogen embrittlement susceptibility of a high-strength AISI 4135 steel by means of a slow strain-rate test (SSRT) using notched round bar specimens. Hydrogen was introduced into the specimens by electrochemical charging and its content was measured by thermal desorption spectrometry (TDS). It was found that the maximum tensile stress decreased in a power law manner with increasing diffusible hydrogen content. Finite element method (FEM) calculations demonstrated that the peak value of the maximum principal stress and the peak value of the locally accumulated hydrogen concentration at the maximum tensile stress were in good agreement with one power law relationship for the specimens with different stress concentration factors.

A Study on the Strength under Pressure of Micro Heat Exchanger

2006 ◽  
Vol 326-328 ◽  
pp. 265-268
Author(s):  
Taek Joon Son ◽  
Young Shin Lee
Keyword(s):  
Stainless Steel ◽  
Fluid Flow ◽  
Heat Exchanger ◽  
Structural Analysis ◽  
Thin Plate ◽  
Thin Plates ◽  
Micro Channel ◽  
Design Guideline ◽  
Micro Heat Exchanger ◽  
Micro Channels

The strength of micro heat exchanger under pressure is studied in this paper. Micro heat exchanger is made with brazing technology. It is constructed of stainless steel thin plates with micro channels and in/out port for fluid flow. Micro channels in thin plates are formed by etching and all parts including thin plates are joined by brazing. The study on the strength under pressure is performed by structural analysis. For structural analysis, one layer of micro heat exchanger body is considered. It is composed of thin plate with micro channel and brazing filler which is used to join thin plates. This paper shows the tendency of stress behavior and gives design guideline of micro heat exchanger.

Limits to elastic response. Yielding and failure

2020 ◽  
pp. 357-368
Author(s):  
Lallit Anand ◽  
Sanjay Govindjee
Keyword(s):  
Shear Stress ◽  
Tensile Stress ◽  
Critical Value ◽  
Maximum Principal Stress ◽  
The Body ◽  
Elastic Response ◽  
Elastic Behaviour ◽  
Pressure Independent ◽  
Yield Conditions ◽  
Is Failure

This chapter presents conditions for determining the limits of elastic behaviour for isotropic materials. The stress invariants of equivalent pressure, equivalent shear stress, and equivalent tensile stress are defined. These are then used to define common yield conditions, viz. the pressure-independent Mises and Tresca yield conditions, as well as the pressure-dependent Coulomb-Mohr and the Drucker-Prager yield conditions. Rankine’s failure criterion for brittle materials in tension, that is failure in a brittle material will initiate when the maximum principal stress at a point in the body reaches a critical value, is also discussed.

scholarly journals Strain-Stress Formation and Deformation of Molded Materials by Drying-Induced Shrinkage

2018 ◽  
Vol 248 ◽  
pp. 01011
Author(s):  
Yoshinori Itaya
Keyword(s):  
Mass Transfer ◽  
Moisture Transfer ◽  
Three Dimensional ◽  
Internal Strain ◽  
Stress Generation ◽  
Heat And Moisture Transfer ◽  
Internal Heating ◽  
Strain Stress ◽  
Stress Formation ◽  
Heat And Moisture

Drying-induced strain-stress and deformation was modeled for molded materials such as ceramics and foods. The transient three-dimensional problem of strain-stress and heat and moisture transfer was solved simultaneously by the finite element method. The behaviors of internal strain-stress formation and deformation are compared among three modes of hot air heating, intermittent heating and internal heating for a ceramic slab. The concepts of the mass transfer potential and a linear viscoelasticity were introduced to consider the different sorption isotherm for layered foods consisting of two ingredients and creep phenomenon. The tensile and compressive stresses fluctuate and fall remarkably during lower heating period when the slab is heated intermittently. In the internal heating mode, drying proceeds fastest as well as stress formation is maintained at the lowest level in the three modes. This effectiveness of the internal heating is investigated experimentally by employing the microwave heating as well. The combination of different foods influences significantly not only the drying characteristic but also the internal strain-stress generation. The drying behavior could be analyzed with a high accuracy even if only heat and moisture transfer were solved without strain-stress analysis. This fact results in that heat and mass transfer and strain-stress are not always necessary to be analyzed simultaneously for saving the CPU time.

Interface Cracks in Kirchhoff Anisotropic Thin Plates of Dissimilar Materials

2013 ◽  
Vol 80 (4) ◽  
Author(s):  
Xu Wang ◽  
Peter Schiavone
Keyword(s):  
Thin Plate ◽  
Interfacial Crack ◽  
Dissimilar Materials ◽  
Thin Plates ◽  
Two Dimensional ◽  
Structure And Properties ◽  
Intensity Factors ◽  
Crack Tip Field ◽  
Anisotropic Plates ◽  
Appl Math

This paper investigates the problem of stretching and bending deformations of a Kirchhoff anisotropic thin plate composed of two dissimilar materials bonded along a straight interface containing a crack. Our analysis makes use of the Stroh octet formalism developed recently by Cheng and Reddy (Cheng and Reddy, 2002, “Octet Formalism for Kirchhoff Anisotropic Plates,” Proc. R. Soc. Lond., A458, pp. 1499–1517; Cheng and Reddy, 2003, “Green’s Functions for Infinite and Semi-Infinite Anisotropic Thin Plates,” ASME J. Appl. Mech., 70, pp. 260–267; Cheng and Reddy, 2004, “Laminated Anisotropic Thin Plate With an Elliptic Inhomogeneity,” Mech. Mater., 36, pp. 647–657; Cheng and Reddy, 2005, “Structure and Properties of the Fundamental Elastic Plate Matrix,” J. Appl. Math. Mech., 85, pp. 721–739) for Kirchhoff anisotropic plates. It is found that the interfacial crack-tip field consists of a pair of two-dimensional oscillatory singularities, which are explicitly determined. Two complex intensity factors are proposed to evaluate the two oscillatory singularities.

Heat and Water Vapor Transport in Fabrics under Ventilated Conditions

1992 ◽  
Vol 62 (7) ◽  
pp. 387-392 ◽  
Author(s):  
George E. R. Lamb
Keyword(s):  
Heat Transfer ◽  
Water Vapor ◽  
Transfer Coefficient ◽  
Moisture Transfer ◽  
Vapor Transport ◽  
Water Vapor Transport ◽  
Air Stream ◽  
Moisture Transfer Coefficient ◽  
The Heat Transfer Coefficient ◽  
Suitable Modification

An expression derived by Take-uchi for the heat transfer coefficient of a fabric exposed to an air stream has been shown to apply (with suitable modification) to the transfer of water vapor through the fabric under the same conditions of ventilation. Experimental and calculated values of the moisture transfer coefficient agree fairly well.

NONLINEAR THIN-PLATE BENDING ANALYSES USING THE HERMITE REPRODUCING KERNEL APPROXIMATION

2012 ◽  
Vol 09 (01) ◽  
pp. 1240012 ◽  
Author(s):  
SATOYUKI TANAKA ◽  
SHOTA SADAMOTO ◽  
SHIGENOBU OKAZAWA
Keyword(s):  
Thin Plate ◽  
Reproducing Kernel ◽  
Geometrical Nonlinearity ◽  
Mathematical Formulation ◽  
Thin Plates ◽  
Plate Bending ◽  
Kernel Approximation ◽  
Hermite Reproducing Kernel Approximation ◽  
Lagrange Strain ◽  
Thin Plate Bending

This study analyzed thin-plate bending problems with a geometrical nonlinearity using the Hermite reproducing kernel approximation and sub-domain-stabilized conforming integration. In thin-plate bending analyses, the deflections and rotations satisfy so-called Kirchhoff mode reproducing conditions. It is then possible to solve large deflection analyses of thin plates, such as elastic bucking problems, with high accuracy and efficiency. Total Lagrangian method is applied to solve the geometrical nonlinearity of the thin plates' deflections and rotations. The Green–Lagrange strain and second Piola–Kirchhoff stress forms are adopted to represent the strains and stresses in the thin plates. Mathematical formulation and some numerical examples are also demonstrated.

FEM Analysis of Failure Process in Thin Film during Wear Test

2010 ◽  
Vol 154-155 ◽  
pp. 1689-1694
Author(s):  
Jin Hua Zheng ◽  
Ying Chen ◽  
Chun Lei Lin ◽  
Xin Li Wei
Keyword(s):  
Tensile Stress ◽  
Failure Process ◽  
Testing Machine ◽  
Film Surface ◽  
Wear Test ◽  
Fem Analysis ◽  
Maximum Tensile Stress ◽  
Maximum Principal Stress ◽  
Parallel Cracks ◽  
Before And After

The semi-circular parallel cracks appeared on the film surface with the angles of 45 degree to the sliding direction of SiC ball and the delamination of film quickly occurred after cracking by using a “ball-on-disk” type testing machine. Stress distribution before and after cracking in the film was calculated by FEM analysis. The maximum tensile stress existing in the film at the back-contact edge of ball is the reason for the initiation of semi-circular parallel cracks. The tensile stress normal to interface as well as the shear stress along interface appears at crack tip, and the alternate generation of these two stresses is the main reason for the delamination. The longitudinal normal stress σxx and the maximum principal stress σ1 become bigger after cracking, so that the crack propagation is faster.

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