The Maximum Stress in Optical Glass Fibers Under Two-Point Bending

2000 ◽  
Vol 123 (1) ◽  
pp. 70-73 ◽  
Author(s):  
Mikio Muraoka
Keyword(s):  
Axial Force ◽  
Maximum Stress ◽  
Optical Glass ◽  
Glass Fibers ◽  
Order Term ◽  
Nonlinear Behavior ◽  
Bending Stress ◽  
Stress Strain ◽  
Nonlinear Stress ◽  
Strain Relationship

The maximum stress in optical glass fibers subjected to two-point bending was evaluated by E. Suhir, “Effect of the Nonlinear Behavior of the Material on Two-Point Bending of Optical Glass Fibers,” ASME Journal of Electronic Packaging, Vol. 114, pp. 246–250, taking into account the shift in the neutral axis due to the nonlinear stress-strain relationship of the materials. However, the resulting distribution of bending stress on the fiber cross-section is not realistic because it produces a nonzero axial force. In the present study, we derive the correct formulas for evaluating the maximum stress under the valid condition that the bending stress does not contribute to the axial force. Moreover, we employ the nonlinear stress-strain relationship containing a third-order term of strain, which is more appropriate for the materials than that utilized by Suhir.

Effect of the Nonlinear Behavior of the Material on Two-Point Bending of Optical Glass Fibers

1992 ◽  
Vol 114 (2) ◽  
pp. 246-250 ◽  
Author(s):  
E. Suhir
Keyword(s):  
Maximum Stress ◽  
Optical Glass ◽  
Glass Fibers ◽  
Nonlinear Behavior ◽  
High Strength ◽  
Large Strains ◽  
Stress Strain ◽  
Maximum Curvature ◽  
Nonlinear Stress ◽  
Strain Relationship

We evaluate the effect of the nonlinear stress-strain relationship on the maximum curvature and maximum stress in optical glass fibers subjected to two-point bending. The analysis uses an assumption that this relationship, obtained experimentally for the case of uniaxial tension (Mallinder and Proctor, 1964; Kraus, Testardi, and Thurston, 1979, Glaesemann, Gulati, and Helfinstine, 1988), holds in the case of compression as well, and is applicable also to bending deformations. We show that the shift in the neutral axis due to the nonlinear stress-strain relationship has a significant effect on the maximum stress, while its effect on the maximum curvature is small and need not be considered. We show also that this relationship, obtained for elastic strains, not exceeding 5 percent, cannot be applied for very large strains, and therefore the future experimental work should include the evaluation of the nonlinear behavior of the material, both in tension and compression, for higher strains and for high strength fibers (such as, for instance, fibers protected by metallic coatings). The obtained results can be helpful in the analysis of optical glass fibers subjected to two-point bending.

scholarly journals NUMERICAL INVESTIGATION OF THE ELASTIC-PLASTIC LINEAR HARDENING STRESS-STRAIN STATE OF THE FRAME ELEMENT CROSS-SECTION

2016 ◽  
Vol 8 (3) ◽  
pp. 94-100
Author(s):  
Andrius Grigusevičius ◽  
Gediminas Blaževičius
Keyword(s):  
Cross Section ◽  
Axial Force ◽  
Cross Sections ◽  
Rectangular Cross Section ◽  
Bending Moment ◽  
Software Environment ◽  
Stress Strain ◽  
Hardening Material ◽  
Frame Element ◽  
Nonlinear Stress

The aim of this paper is to present a solution algorithm for determining the frame element crosssection carrying capacity, defined by combined effect of bending moment and axial force. The distributions of stresses and strains inside a cross-section made of linearly hardening material are analysed. General nonlinear stress-strain dependencies are composed. All relations are formed for rectangular cross-section for all possible cases of combinations of axial force and bending moment. To this end, five different stress-strain states are investigated and four limit axial force values are defined in the present research. The nonlinear problem is solved in MATLAB mathematical software environment. Stress-strain states in the cross-sections are investigated in detail and graphically analysed for two numerical experiments.

Studies on the Stress-Strain Relationship Bovine Cortical Bone Based on Ramberg–Osgood Equation

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
N. K. Sharma ◽  
M. D. Sarker ◽  
Saman Naghieh ◽  
Daniel X. B. Chen
Keyword(s):  
Cortical Bone ◽  
Linear Regression Analysis ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Loading Conditions ◽  
Stress Strain ◽  
Strain Behavior ◽  
Nonlinear Stress ◽  
Strain Relationship ◽  
Relationship Of

Bone is a complex material that exhibits an amount of plasticity before bone fracture takes place, where the nonlinear relationship between stress and strain is of importance to understand the mechanism behind the fracture. This brief presents our study on the examination of the stress–strain relationship of bovine femoral cortical bone and the relationship representation by employing the Ramberg–Osgood (R–O) equation. Samples were taken and prepared from different locations (upper, middle, and lower) of bone diaphysis and were then subjected to the uniaxial tensile tests under longitudinal and transverse loading conditions, respectively. The stress–strain curves obtained from tests were analyzed via linear regression analysis based on the R–O equation. Our results illustrated that the R–O equation is appropriate to describe the nonlinear stress–strain behavior of cortical bone, while the values of equation parameters vary with the sample locations (upper, middle, and lower) and loading conditions (longitudinal and transverse).

Stress-Strain Behaviour of Dielectric Elastomer for Actuators

2015 ◽  
Vol 789-790 ◽  
pp. 837-841 ◽  
Author(s):  
R.K. Sahu ◽  
K. Patra ◽  
S. Bhaumik ◽  
A.K. Pandey ◽  
D.K. Setua
Keyword(s):  
Strain Rate ◽  
Maximum Stress ◽  
Dielectric Elastomer ◽  
Cyclic Softening ◽  
Hysteresis Loss ◽  
Commercial Application ◽  
Stress Strain ◽  
Rate Dependent ◽  
Nonlinear Stress ◽  
Loading Case

Dielectric elastomer (DE) is gaining importance for potential strategic and commercial application as actuators. This paper reports the experimental investigation on different mechanical phenomena at large deformation of a commercially available acrylic dielectric elastomer material, VHB 4910 (3M) which is widely used for dielectric elastomer actuator (DEA) research. Attempts are made for accurate and precise experimental determination of nonlinear stress-strain, strain rate dependent hysteresis behaviour and cyclic softening of this material. It is observed that with the increase in strain rate maximum stress at a particular strain increases whereas hysteresis loss decreases. In the cyclic loading case after a particular number of cycles almost the hysteresis loss and maximum stress becomes constant. These experimental results are likely to be interesting for the designers for proper designing and characterization of the actuators fabricated with this material.

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