Numerical study of GFRP joints bearing strength reduction due to drilling-induced delamination

2019 ◽  
Vol 54 (16) ◽  
pp. 2185-2194 ◽  
Author(s):  
M Safarabadi ◽  
M Sardar
Keyword(s):  
Parametric Study ◽  
Cohesive Zone ◽  
Volume Fraction ◽  
Numerical Study ◽  
Load Carrying Capacity ◽  
Zone Method ◽  
Bearing Strength ◽  
Load Carrying ◽  
Negative Effect ◽  
Good Agreement

Delamination is one of the most common defects caused by drilling, which can have negative effect on the joint performance. This study investigates the effect of delamination on the bearing strength of [0/90]2s, [15/−75]2s, [30/−60]2s and [45/−45]2s GFRP layers numerically. Cohesive zone method and virtual crack closure technique have been used for delamination modeling and the results of these two methods have been compared. FEM results show good agreement with available experimental data. Results demonstrated that delamination reduces the bearing strength. Among four different stacking sequences, delamination has the most effect on the laminate with the stacking sequence of [0/90]2s. In both delaminated and non-delaminated models, [0/90]2s and [45/−45]2s stacking sequences have the most and the least bearing strength, respectively. By increasing the radius of delaminated zone from 3 mm to 15 mm, bearing strength does not change a lot. As the delaminated zone reaches the edge of the specimen, bearing strength reduces strongly because the layers separate completely and the load-carrying capacity reduces. A parametric study was also conducted to examine the effects of different factors. The results of parametric study showed that by increasing the volume fraction of the fiber as well as the use of carbon fiber instead of glass fiber, the bearing strength increases.

A Parametric Numerical Study of Radiative Transfer in Thermotropic Materials

2013 ◽  
Author(s):  
Adam C. Gladen ◽  
Susan C. Mantell ◽  
Jane H. Davidson
Keyword(s):  
Particle Size ◽  
Radiative Transfer ◽  
Optical Thickness ◽  
Parametric Study ◽  
Volume Fraction ◽  
Numerical Study ◽  
Anisotropic Scattering ◽  
Index Of Refraction ◽  
Spherical Particles ◽  
Size Parameter

A thermotropic material is modeled as an absorbing, thin slab containing anisotropic scattering, monodisperse, spherical particles. Monte Carlo ray tracing is used to solve the governing equation of radiative transfer. Predicted results are validated by comparison to the measured normal-hemispherical reflectance and transmittance of samples with various volume fraction and relative index of refraction. A parametric study elucidates the effects of particle size parameter, scattering albedo, and optical thickness on the normal-hemispherical transmittance, reflectance, and absorptance. The results are interpreted for a thermotropic material used for overheat protection of a polymer solar absorber. For the preferred particle size parameter of 2, the optical thickness should be less than 0.3 to ensure high transmittance in the clear state. To significantly reduce the transmittance and increase the reflectance in the translucent state, the optical thickness should be greater than 2.5 and the scattering albedo should be greater than 0.995. For optical thickness greater than 5, the reflectance is asymptotic and any further reduction in transmittance is through increased absorptance. A case study is used to illustrate how the parametric study can be used to guide the design of thermotropic materials. Low molecular weighted polyethylene in poly(methyl methacrylate) is identified as a potential thermotropic material. For this material and a particle radius of 200 nm, it is determined that the volume fraction and thickness should equal 10% and 1 mm, respectively.

scholarly journals Design of steering system of a buggy

2020 ◽  
Vol 327 ◽  
pp. 03004
Author(s):  
D. Santana Sanchez ◽  
A. Mostafa
Keyword(s):  
Carrying Capacity ◽  
Steering System ◽  
Nonlinear Finite Element ◽  
Load Carrying Capacity ◽  
Dynamic Effects ◽  
Flexural Behaviour ◽  
Steering Angle ◽  
Load Carrying ◽  
And Performance ◽  
Good Agreement

The present paper discusses the design analysis and limitations of the steering system of a buggy. Many geometrical and performance characteristics of the designed steering system were considered to address the kinematic constraints and load carrying capacity of the steering elements. Ackremann geometry approach was used to assess the limiting steering angle, while Lewis bending formula with the inclusion of dynamic effects was employed to characterise the flexural properties of the rack and pinion steering system. Analytical results were numerically verified using ABAQUS/Explicit nonlinear finite element (FE) package. Good agreement has been achieved between analytical and numerical results in predicting the flexural behaviour of the steering rack and pinion system.

scholarly journals Micromechanical Analyses of Debonding and Matrix Cracking in Dual-Phase Materials

2016 ◽  
Vol 83 (5) ◽  
Author(s):  
Brian Nyvang Legarth ◽  
Qingda Yang
Keyword(s):  
Biaxial Loading ◽  
Matrix Cracking ◽  
Dual Phase ◽  
Load Carrying Capacity ◽  
Matrix Cracks ◽  
Loading Direction ◽  
Load Carrying ◽  
The Matrix ◽  
Cohesive Zones ◽  
Good Agreement

Failure in elastic dual-phase materials under transverse tension is studied numerically. Cohesive zones represent failure along the interface and the augmented finite element method (A-FEM) is used for matrix cracking. Matrix cracks are formed at an angle of 55 deg−60 deg relative to the loading direction, which is in good agreement with experiments. Matrix cracks initiate at the tip of the debond, and for equi-biaxial loading cracks are formed at both tips. For elliptical reinforcement the matrix cracks initiate at the narrow end of the ellipse. The load carrying capacity is highest for ligaments in the loading direction greater than that of the transverse direction.

The effect of V-shape protruded and dimple textured on the load-carrying capacity and coefficient of friction of hydrodynamic journal bearing: A comparative numerical study

2020 ◽  
pp. 135065012093500
Author(s):  
Sanjay Sharma ◽  
Aniket Sharma ◽  
Gourav Jamwal ◽  
Rajeev Kumar Awasthi
Keyword(s):  
Coefficient Of Friction ◽  
Carrying Capacity ◽  
Performance Enhancement ◽  
Numerical Study ◽  
Geometrical Parameters ◽  
Load Carrying Capacity ◽  
Enhancement Ratio ◽  
Load Carrying ◽  
The Coefficient Of Friction ◽  
Computing Performance

The present comparative numerical study is between V-shape protruded, dimple textured, and untextured bearing. The performance parameters in terms of the load-carrying capacity and coefficient of friction are computed by solving governing Reynold’s equation of the lubricant fluid flow. The governing equation is solved by the finite element method by assuming that the fluid is Newtonian and isoviscous in nature. The effect of eccentricity ratios, texture distribution, texture heights, and texture depths are considered for the analysis in both textured bearings. From simulated results, the load-carrying capacity and coefficient of friction is found to be maximum for protruded textured bearing in full textured region and first half-textured region respectively as compared to untextured bearings. Finally, optimal operating and geometrical parameters of textured bearing is obtained by computing performance enhancement ratio, which is the ratio of the load-carrying capacity to the coefficient of friction. The maximum value of the performance enhancement ratio is found for protruded and dimple textured bearing in full texturing and second half-region corresponding to the eccentricity ratio of 0.8 and 0.6 respectively at texture height and depth of 0.4.

Theoretical Investigation of Couple Stress Squeeze Films in a Curved Circular Geometry

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Vimala Manivasakan ◽  
Govindarajan Sumathi
Keyword(s):  
Theoretical Investigation ◽  
Carrying Capacity ◽  
Couple Stress ◽  
Squeeze Flow ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Fluid Inertia ◽  
Load Carrying ◽  
Inertia Forces ◽  
Good Agreement

A theoretical investigation of the laminar squeeze flow of a couple-stress fluid between a flat circular static disk and an axisymmetric curved circular moving disk has been carried out using modified lubrication theory and microcontinuum theory. The combined effects of fluid inertia forces, curvature of the disk and non-Newtonian couple stresses on the squeeze film behavior are investigated analytically. Each of these effects and their combinations show a significant enhancement in the squeeze film behavior, and these are studied through their effects on the squeeze film pressure and the load carrying capacity of the fluid film as a function of time. Two different forms of the gapwidth between the disks have been considered, and the results have been shown to be in good agreement with the existing literature.

Applicability of Net-Section Collapse Load Approach to Maximum Load Predictions of Multiple Circumferential Cracked Pipes: Numerical Study

2015 ◽  
Author(s):  
Myeong-Woo Lee ◽  
Seung-Jae Kim ◽  
So-Dam Lee ◽  
Jun-Young Jeon ◽  
Yun-Jae Kim
Keyword(s):  
Experimental Data ◽  
Numerical Method ◽  
Test Data ◽  
Numerical Study ◽  
Maximum Load ◽  
Load Carrying Capacity ◽  
Collapse Load ◽  
Crack Geometry ◽  
Large Sets ◽  
Load Carrying

To estimate maximum load-carrying capacity of pipes with multiple circumferential cracks, the net-section collapse load approach has been proposed. Although the proposed method has been validated against pipe test data, experimental data are quite limited due to large sets of variables to be considered. In this paper, a numerical method is proposed to generate virtual pipe test data with wide ranges of crack geometry and interspacing. To get confidence of the proposed numerical method, it is firstly applied to simulate existing 4-inch diameter schedule 80 pipes with two circumferential cracks. Predicted maximum loads agree well with experimental data. Then the proposed method is applied to generate maximum loads for wider ranges of crack geometry and loading conditions. It is found that the net-section collapse load approach works well for all cases considered.

Load-Carrying Behaviour of Dowel-Type Timber Connections with Multiple Slotted-in Steel Plates

2011 ◽  
Vol 94-96 ◽  
pp. 43-47
Author(s):  
Xin Hai Fan ◽  
Sheng Dong Zhang ◽  
Wen Jun Qu
Keyword(s):  
Carrying Capacity ◽  
Steel Plates ◽  
Load Carrying Capacity ◽  
Timber Structures ◽  
Lateral Loads ◽  
Large Cross Section ◽  
Load Carrying ◽  
Timber Connections ◽  
Dowel Connection ◽  
Good Agreement

The multiple-shear dowel connection with slotted-in steel plates is one of the most efficient joints for large cross section timber structures. Experiments were performed on dowel-type timber connections with one, two and three slotted in steel plates under lateral loads parallel to the grain. Test variables include the number of steel plates, the spacing of the steel plates, and the dowel diameter. Results show that the load-carrying capacity of the dowel-type connection increased as the number and spacing of steel plates in the same thickness of timber specimens. Finally, a model of the load-carrying capacity of multiple shear steel-to-timber connections is presented, which showed good agreement with the results obtained in the experiment.

scholarly journals Experimental and Numerical Study of Seismic Performance of Precast Prestressed Concrete Frame Internal Connection

2015 ◽  
pp. 406-413
Author(s):  
Xiandong Liao ◽  
Xiang Hu
Keyword(s):  
Seismic Performance ◽  
Prestressed Concrete ◽  
Carrying Capacity ◽  
Numerical Study ◽  
Scale Model ◽  
Load Carrying Capacity ◽  
Concrete Frame ◽  
Internal Connection ◽  
Load Carrying ◽  
Precast Prestressed Concrete

The seismic performance of the internal connection of precast prestressed concrete frame was studied systematically, based on the experiment of full-scale model under low cyclic reversed loading. This study was mainly focused on failure pattern, load-carrying capacity, skeleton curves, and hysteresis curves. Furthermore, a nonlinear finite element analysis using Abaqus was carried out to study the characteristics of the internal connection of precast prestressed concrete frame. Results revealed that the damage was concentrated mainly on beam end owing to flexural action, while steel bars in the columns and stirrups in the core region remained elastic until failure occurred. The calculated value of the load-carrying capacity of the internal connection was similar to the experimental one. Present study can be referenced for the application of precast prestressed concrete frame in high seismic zones.

Pitting Resistance and Bending Strength of Bevel and Hypoid Gear Teeth

1992 ◽  
Author(s):  
B.-R. Höhn ◽  
H. Winter ◽  
K. Michaelis ◽  
F. Vollhüter
Keyword(s):  
Bending Strength ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Hypoid Gear ◽  
Hypoid Gears ◽  
Gear Teeth ◽  
Bevel Gears ◽  
Load Carrying ◽  
Calculation Results ◽  
Good Agreement

Abstract Bevel and hypoid gears are widely used for gears with crossed axis. The influence of a pinion offset on the load carrying capacity — pitting resistance and bending strength — is introduced in a different way in commonly used calculation methods. Load carrying and measurement investigations on the influence of pinion offset on pitting resistance and bending strength are reported. Tests show an increasing bending strength and decreasing maximum tooth root stresses with increasing pinion offset. Also a slight increase of pitting resistance and a slight decrease of the Hertzian pressure was evaluated. The load carrying calculation results for bevel gears without pinion offset, DIN 3991, is in good agreement with test results. The bending strength of hypoid gears calculated according to Niemann/Winter, is greater than that experimentally measured. For pitting resistance, however, the calculation is less than the measured results.

Sign in / Sign up

Export Citation Format

Share Document