Indian Journal of Engineering & Materials Sciences Vol. 15, December 2008, pp. 452-458 Effect of fibre orientation on stress concentration factor in a laminate with central circular hole under transverse static loading N D Mittal* & N K J ain Department of Applied Mechanics, Maulana Azad National Institute of Technology, Bhopal 462 007, India Received 12 April 2 007; revise d received 17 June 20 08The effect of fibre orientation ( θ) on stress concentration factor (SCF) in a rectangular composite laminate with central circular hole under transverse static loading has been studied by using finite element method. The percent variations in deflection with fibre orientation are also compared with deflection in laminate without hole. Studies are carried out for three D/A ratios (whereD is hole diameter and A is plate width). The results are obtained for four different boundary conditions. Three different types of materials are used for whole analysis to find the sensitivity of stress concentration with elastic constants. A finite element study is made for whole analysis of laminate with a central hole under transverse static loading. Keywords: Finite element method, Stress concentration factor, Composite, Laminate, material properties, Fibre orientation, Transverse loading A laminated composite plate with central circular hole have found widespread applications in various fields of engineering such as aerospace, marine, automobile and mechanical. Stress concentration arises from any abrupt change in geometry of plate under loading. As a result, stress distribution is not uniform throughout the cross-section. Failures such as fatigue cracking and plastic deformation frequently occur at points ofstress concentration. Hence, for the design of a laminated composite plate with central circular hole, stress concentration factor plays an important role and accurate knowledge of stresses and stress concentration factor at the edges of hole under in plane or transverse loading are required. Analytical solutions are available in the literature for prediction of SCF in different types of abrupt changes in shape. Shastry and Raj 1 have analysed the effect of fibre orientation for a unidirectional composite laminate with finite element method by assuming a plane stress problem under in plane static loading. Paul and Rao 2,3 presented a theory for evaluation of stress concentration factor of thick and FRP laminated plate with the help of Lo-Christensen-Wu higher order bending theory under transverse loading. Xiwu et al. 4,5 evaluated stress concentration of finite composite laminates with elliptical hole and multiple elliptical holes based on classical laminated plate theory. Iwaki 6 worked on stress concentrations in a plate with two unequal circular holes. Ukadgaonker and Rao 7 proposed a general solution for stresses around holes in symmetric laminates by introducing a general form of mapping function and an arbitrary biaxial loading condition into the boundary conditions. Ting et al. 8 presented a theory for stress analysis by using rhombic array of alternating method for multiple circular holes. Chaudhuri 9 worked on stress concentration around a part through hole weakening a laminated plate by finite element method. Mahiou and Bekaou 10 studied for local stress concentration and for the prediction of tensile failure in unidirectional composites. Toubal et al. 11 studied experimentally for stress concentration in a circular hole in composite plate. Younis 12 investigated by reflected photoelasticity method that the assembly stress are the result of contact and bearing stresses between the bolts and member, contributes to reducing stresses around the circular holes in a plate under uniaxial tension. Peterson 18 has developed good theory and charts on the basis of mathematical analysis and presented excellent mythology in graphical form for evaluation of stress concentration factors in isotropic plates with different types ofabrupt change, but no results are presented for orthotropic and laminated plate. In this paper, a study of rectangular laminated composite plate with central circular hole for the effect of fibre orientation on stress concentration factor under transverse static loading is made. The analytical treatment for such type of problem is very difficult and hence the finite element method is __________ *For correspondence (E-mail: [email protected])
7
Embed
Effect of Fiber Orientation on Stress Concentration Factor in a Laminate With Central Circular Hole Under Transverse Static Loading
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
7/28/2019 Effect of Fiber Orientation on Stress Concentration Factor in a Laminate With Central Circular Hole Under Transverse Static Loading
Indian Journal of Engineering & Materials SciencesVol. 15, December 2008, pp. 452-458
Effect of fibre orientation on stress concentration factor in a laminate with central
circular hole under transverse static loading
N D Mittal* & N K Jain
Department of Applied Mechanics, Maulana Azad National Institute of Technology, Bhopal 462 007, India
Received 12 April 2007; revised received 17 June 2008
The effect of fibre orientation (θ) on stress concentration factor (SCF) in a rectangular composite laminate with centralcircular hole under transverse static loading has been studied by using finite element method. The percent variations indeflection with fibre orientation are also compared with deflection in laminate without hole. Studies are carried out for three
D/A ratios (where D is hole diameter and A is plate width). The results are obtained for four different boundary conditions.
Three different types of materials are used for whole analysis to find the sensitivity of stress concentration with elastic
constants. A finite element study is made for whole analysis of laminate with a central hole under transverse static loading.Keywords: Finite element method, Stress concentration factor, Composite, Laminate, material properties, Fibre orientation,
Transverse loading
A laminated composite plate with central circular hole
have found widespread applications in various fields
of engineering such as aerospace, marine, automobile
and mechanical. Stress concentration arises from any
abrupt change in geometry of plate under loading. As
a result, stress distribution is not uniform throughout
the cross-section. Failures such as fatigue cracking
and plastic deformation frequently occur at points of
stress concentration. Hence, for the design of alaminated composite plate with central circular hole,
stress concentration factor plays an important role and
accurate knowledge of stresses and stress
concentration factor at the edges of hole under in
plane or transverse loading are required. Analytical
solutions are available in the literature for prediction
of SCF in different types of abrupt changes in shape.
Shastry and Raj1 have analysed the effect of fibre
orientation for a unidirectional composite laminate
with finite element method by assuming a plane stress
problem under in plane static loading. Paul and Rao2,3
presented a theory for evaluation of stressconcentration factor of thick and FRP laminated plate
with the help of Lo-Christensen-Wu higher order
bending theory under transverse loading. Xiwu
et al.4,5
evaluated stress concentration of finite
composite laminates with elliptical hole and multiple
elliptical holes based on classical laminated plate
theory. Iwaki6 worked on stress concentrations in a
plate with two unequal circular holes. Ukadgaonker
and Rao7 proposed a general solution for stresses
around holes in symmetric laminates by introducing a
general form of mapping function and an arbitrary
biaxial loading condition into the boundary
conditions. Ting et al.8
presented a theory for stress
analysis by using rhombic array of alternating method
for multiple circular holes. Chaudhuri9 worked on
stress concentration around a part through hole
weakening a laminated plate by finite elementmethod. Mahiou and Bekaou10
studied for local stress
concentration and for the prediction of tensile failure
in unidirectional composites. Toubal et al.11 studied
experimentally for stress concentration in a circular
hole in composite plate. Younis12 investigated by
reflected photoelasticity method that the assembly
stress are the result of contact and bearing stresses
between the bolts and member, contributes to
reducing stresses around the circular holes in a plate
under uniaxial tension. Peterson18 has developed good
theory and charts on the basis of mathematical
analysis and presented excellent mythology ingraphical form for evaluation of stress concentration
factors in isotropic plates with different types of
abrupt change, but no results are presented for
orthotropic and laminated plate.
In this paper, a study of rectangular laminated
composite plate with central circular hole for theeffect of fibre orientation on stress concentration
factor under transverse static loading is made. The
analytical treatment for such type of problem is very
difficult and hence the finite element method is__________*For correspondence (E-mail: [email protected])
7/28/2019 Effect of Fiber Orientation on Stress Concentration Factor in a Laminate With Central Circular Hole Under Transverse Static Loading