A new formulation of continuous transverse shear stress field for static and dynamic analysis of sandwich beams with soft core

2019 ◽  
Vol 121 (8) ◽  
pp. 1847-1876 ◽  
Author(s):  
Shanhong Ren ◽  
Guozhong Zhao
Keyword(s):  
Shear Stress ◽  
Stress Field ◽  
Dynamic Analysis ◽  
Transverse Shear ◽  
Soft Core ◽  
Sandwich Beams ◽  
Transverse Shear Stress ◽  
Static And Dynamic Analysis ◽  
New Formulation ◽  
Shear Stress Field

Vibration of laminated sandwich beams having soft core

2011 ◽  
Vol 18 (10) ◽  
pp. 1422-1435 ◽  
Author(s):  
Hanuman Devidas Chalak ◽  
Anupam Chakrabarti ◽  
Mohamad Asharaf Iqbal ◽  
Abdul Hamid Sheikh
Keyword(s):  
Shear Stress ◽  
Free Vibration ◽  
Transverse Shear ◽  
Soft Core ◽  
Future Research ◽  
Transverse Displacement ◽  
Beam Model ◽  
Sandwich Beams ◽  
Transverse Shear Stress ◽  
The Core

Free vibration response of laminated sandwich beams having a soft core is studied by using a recently developed C0 finite element beam model. The model has been developed based on higher order zigzag theory where the in-plane displacement variation is considered to be cubic for both the face sheets and the core. The transverse displacement is assumed to be quadratic within the core while it remains constant in the faces beyond the core. The model satisfies the condition of transverse shear stress continuity at the layer interfaces and the zero transverse shear stress condition at the top and bottom of the beam. The nodal field variables are chosen in an efficient manner to overcome the problem of continuity requirement of the derivatives of transverse displacements. Numerical examples on free vibration covering different features of laminated composite and sandwich beams are presented. Many new results are also presented which should be useful for future research.

VIBRATION AND BUCKLING ANALYSIS OF LAMINATED SANDWICH PLATE HAVING SOFT CORE

2013 ◽  
Vol 13 (08) ◽  
pp. 1350034 ◽  
Author(s):  
RAVI PRAKASH KHANDELWAL ◽  
ANUPAM CHAKRABARTI ◽  
PRADEEP BHARGAVA
Keyword(s):  
Shear Stress ◽  
Free Vibration ◽  
Displacement Field ◽  
Transverse Shear ◽  
Sandwich Plate ◽  
Soft Core ◽  
Transverse Displacement ◽  
Fe Model ◽  
Transverse Shear Stress ◽  
The Core

Free vibration and buckling of laminated sandwich plate having soft core is studied by using an efficient C0 continuous finite element (FE) model based on higher-order zigzag theory (HOZT). In this theory, the in-plane displacement field for both the face sheets and the core is obtained by superposing a global cubically varying displacement field on a zigzag linearly varying displacement field with a different slope in each layer. The transverse displacement is assumed to be quadratic within the core while it remains constant in the faces beyond the core. The proposed model satisfies the condition of transverse shear stress continuity at the layer interfaces and the zero transverse shear stress condition at the top and bottom of the plate. The nodal field variables are chosen in an efficient manner to overcome the problem of C1 continuity requirement of the transverse displacement. Numerical examples on free vibration and buckling covering different geometric and material features of laminated composite and sandwich plates are presented. Many new results are also presented which should be useful for future research.

scholarly journals A New C0 2D Fe Model Based on Improved Higher Order Zigzag Theory for the Analysis of Soft Core Sandwich Plate

2013 ◽  
Vol 18 (2) ◽  
pp. 395-423 ◽  
Author(s):  
R.P. Khandelwal ◽  
A. Chakrabarti ◽  
P. Bhargava
Keyword(s):  
Shear Stress ◽  
Displacement Field ◽  
Transverse Shear ◽  
Sandwich Plate ◽  
Higher Order ◽  
Least Square ◽  
Soft Core ◽  
Fe Model ◽  
Transverse Shear Stress ◽  
The Core

An efficient C0 continuous finite element (FE) model is developed based on a combined theory (refine higher order shear deformation theory (RHSDT) and least square error (LSE) method) for the static analysis of a soft core sandwich plate. In this (RHSDT) theory, the in-plane displacement field for the face sheets and the core is obtained by superposing a global cubically varying displacement field on a zig-zag linearly varying displacement field with a different slope in each layer. The transverse displacement assumes to have a quadratic variation within the core and it remains constant in the faces beyond the core. The proposed model satisfies the condition of transverse shear stress continuity at the layer interfaces and the zero transverse shear stress condition at the top and bottom of the sandwich plate. The nodal field variables are chosen in an efficient manner to circumvent the problem of C1 continuity requirement of the transverse displacements. In order to calculate the accurate through thickness transverse stresses variation, the Least Square Error (LSE) method has been used at the post processing stage. The proposed combined model (RHSDT and LSE) is implemented to analyze the laminated composites and sandwich plates. Many new results are also presented which should be useful for future research.

Determination of the transverse shear stress in layered composites

2020 ◽  
Vol 86 (2) ◽  
pp. 44-53
Author(s):  
Yu. I. Dudarkov ◽  
M. V. Limonin
Keyword(s):  
Shear Stress ◽  
Transverse Shear ◽  
Composite Beam ◽  
Layered Composite ◽  
Equivalent Model ◽  
Shear Stresses ◽  
Transverse Shear Stress ◽  
Layered Composites ◽  
Laminate Composites ◽  
Transverse Shear Stresses

An engineering approach to estimation of the transverse shear stresses in layered composites is developed. The technique is based on the well-known D. I. Zhuravsky equation for shear stresses in an isotropic beam upon transverse bending. In general, application of this equation to a composite beam is incorrect due to the heterogeneity of the composite structure. According to the proposed method, at the first stage of its implementation, a transition to the equivalent model of a homogeneous beam is made, for which the Zhuravsky formula is valid. The transition is carried out by changing the shape of the cross section of the beam, provided that the bending stiffness and generalized elastic modulus remain the same. The calculated shear stresses in the equivalent beam are then converted to the stress values in the original composite beam from the equilibrium condition. The main equations and definitions of the method as well as the analytical equation for estimation of the transverse shear stress in a composite beam are presented. The method is verified by comparing the analytical solution and the results of the numerical solution of the problem by finite element method (FEM). It is shown that laminate stacking sequence has a significant impact both on the character and on the value of the transverse shear stress distribution. The limits of the applicability of the developed technique attributed to the conditions of the validity of the hypothesis of straight normal are considered. It is noted that under this hypothesis the shear stresses do not depend on the layer shear modulus, which explains the absence of this parameter in the obtained equation. The classical theory of laminate composites is based on the similar assumptions, which gives ground to use this equation for an approximate estimation of the transverse shear stresses in in a layered composite package.

Transverse shear stress within surface layer and its effects

2019 ◽  
Vol 25 (2) ◽  
pp. 166-180
Author(s):  
Ge Yan ◽  
Zaixing Huang
Keyword(s):  
Shear Stress ◽  
Surface Layer ◽  
Hydrostatic Pressure ◽  
Transverse Shear ◽  
Transverse Shear Stress ◽  
Middle Section ◽  
Nanoscale Solids ◽  
Maximal Stress

When the transverse shear stress within a surface layer is taken into account, what happens in the deformation of micro- or nanoscale solids? The relevant problems are investigated by analyzing the deformation of a micro- or nanosized solid ellipsoid. The results show that both the stress and the deformation of a micro- or nanosized ellipsoid increase after the transverse shear stress within the surface layer is introduced, and that the maximal stress always occurs at both ends of the long axis of the ellipsoid. Unlike the prediction given by the Gurtin–Murdoch model, the calculation coming from the model of this paper predicts that the micro- or nanosized ellipsoid subjected to hydrostatic pressure contracts radially in the middle section and expands radially on both sides of the middle section. This difference provides an experimental standard to verify two models.

Cell adhesion on gaseous plasma modified poly-(l-lactide) surface under shear stress field

Biomaterials ◽  
2003 ◽  
Vol 24 (21) ◽  
pp. 3757-3764 ◽  
Author(s):  
Yuqing Wan ◽  
Jian Yang ◽  
Junlin Yang ◽  
Jianzhong Bei ◽  
Shenguo Wang
Keyword(s):  
Shear Stress ◽  
Cell Adhesion ◽  
Stress Field ◽  
Gaseous Plasma ◽  
Shear Stress Field

An Evaluation of a Modified Iosipescu Specimen for Measurement of Elastic-Plastic Properties of Solder Materials

2010 ◽  
Author(s):  
Subhasis Mukherjee ◽  
Abhijit Dasgupta
Keyword(s):  
Shear Stress ◽  
Stress Field ◽  
Solder Joint ◽  
Scale Effects ◽  
Element Model ◽  
Test Material ◽  
Plastic Properties ◽  
Elastic Plastic ◽  
Uniform Shear ◽  
Shear Stress Field

There are various specimen configurations available in the literature for characterizing the mechanical behavior of solder interconnect materials. An ideal test specimen should use a simple geometry to minimize the complexity of the stress analysis and which produces a uniform material response throughout the test material. In the thermo-mechanical micro scale (TMM) test used in this study, we use a simple, notched shear specimen, based on a concept originally proposed by Iosipescu [1967] [1], which produces a very uniform shear stress field in the solder joint volume [Reinikainen et al., 1998] [2]. Our modified Iosipescu specimen comprises of two oxygen free, high conductivity (OFHC) copper platens soldered together and loaded in simple shear. The solder joint in this specimen is only 180 microns wide to capture the length scale effects of functional solder interconnects. This study examines the effects of dimensional variabilities of this modified Iosipescu specimen on the shear stress distribution in the solder joint. Variabilities encountered in these specimens include: (i) fillets at the V-notches, caused by excess solder; (ii) offset between the two copper platens along the loading direction; (iii) taper of the solder joint due to lack of parallelism of the edges of the copper platens; and (iv) misalignment between the specimen centerline and loading axis of the TMM test frame due to mounting variability. Detailed parametric studies of these four dimensional variations in the TMM specimen are conducted using a simple two-dimensional elastic-plastic finite element model. The uniformity of the shear stress field in the specimen is investigated and the variation in the derived stress-strain curves is examined, as a function of the dimensional variabilities described above.

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