Geometric Nonlinear Effect On Biaxial Bending Strength of Thin Silicon Die in the Ball-On-Ring Test

2021 ◽  
Author(s):  
Ming-Yi Tsai ◽  
H. Y. Liu
Keyword(s):  
Linear Theory ◽  
Large Deflection ◽  
Bending Strength ◽  
Test Method ◽  
Bending Test ◽  
Ring Test ◽  
Specimen Thickness ◽  
Biaxial Bending ◽  
Geometric Nonlinear ◽  
Thin Silicon

Abstract The ball-on-ring (BoR) test, one of the most popular biaxial bending tests, is thoroughly investigated in this study for determining the bending strength of thin silicon dies. The application of this test method with a linear theory to the thin dies is also reevaluated using a nonlinear finite element method (NFEM) by taking into account the geometric nonlinearities, including large-deflection (global) and contact (local) nonlinearities. Mechanics of the BoR test is also discussed in terms of geometric linearity and nonlinearity. It is found that the bending strength calculated by the existing linear theory for the BoR test is still valid for the non-thin die specimens, but not for thin ones. The reason is that the thin-die specimens in the test suffer a contact-nonlinearity effect, due to a maximum applied stress moving away from the loading pin center during the loading process. The global geometric nonlinear (large-deflection) behavior occurring in the three-point bending test is not observed in the test. For applications, the fitting equations of the maximum stress in terms of applied load are proposed based on the NFEM results. Those fitting equations only depend on the specimen thickness, the head radius of the loading pin, and the elastic modulus of the specimen, but not on the specimen radius, a supporting ring radius and the head radius of the ring. The 110 µm and 160 µm-thick silicon dies in the BoR test are also demonstrated with the related fitting equations.

Geometric Nonlinear Effect on Biaxial Bending Strength of Thin Silicon Die in the PoEF Test

2020 ◽  
Vol 20 (2) ◽  
pp. 442-451
Author(s):  
Ming-Yi Tsai ◽  
Jia-Hao Yeh ◽  
Pu-Shan Huang ◽  
D. L. Chen ◽  
M. K. Shih ◽  
...  
Keyword(s):  
Nonlinear Effect ◽  
Bending Strength ◽  
Biaxial Bending ◽  
Geometric Nonlinear ◽  
Thin Silicon

Experimental Study on the Size Effect on Flexural Behavior of Larch Glulam Beams

2016 ◽  
Vol 847 ◽  
pp. 3-9 ◽  
Author(s):  
Xian Yan Zhou ◽  
Lei Cao ◽  
Dan Zeng
Keyword(s):  
Size Effect ◽  
Large Scale ◽  
Bending Strength ◽  
Weibull Model ◽  
Test Method ◽  
Flexural Behavior ◽  
Bending Test ◽  
Glulam Beam ◽  
Bending Modulus ◽  
Size Adjustment

At present, design values in codes and regulations are mainly based on test results of small size specimens, which are different from large-scale members used in practical engineering, therefore size adjustment coefficients are needed to be established. The four-point bending test method was adopted to investigate four groups of different sizes of Larch Glulam beams in their flexural behavior. Experiment data such as ultimate bearing capacity, deflection, strains and others are obtained, and the failure pattern and failure mechanism of bending members are analyzed. The research results indicate that the bending modulus of elasticity of Larch Glulam beam is not affected by the size. Bending strength of the Larch Glulam beam show a declining trend as the size of specimens increases, however, the ultimate bending moment increases. In addition, by means of a two-parameter Weibull model, a so-called size effect coefficient has been calculated by the slope method, thus providing a basis for the design and application of Larch Glulam beams.

scholarly journals A Method for Assessing Axial and Temporal Effects of the Leaf Sheath on the Flexural Stiffness of the Maize Stem

2021 ◽  
Author(s):  
Jared Hale ◽  
Spencer Webb ◽  
Nathan Hale ◽  
Christopher Stubbs ◽  
Douglas D Cook
Keyword(s):  
Bending Strength ◽  
Statistical Significance ◽  
Temporal Patterns ◽  
Leaf Sheath ◽  
Test Method ◽  
Bending Test ◽  
Flexural Stiffness ◽  
Spatial And Temporal Patterns ◽  
Three Point Bending ◽  
Non Destructive

Abstract Background: The leaf sheath of many plants has been observed to influence both stiffness of the stem and ultimate strength. The leaf sheath has been implicated in studies of maize “greensnap” (or “brittle-snap”) failure. However, but the influence of the sheath is still not well understood and few methods exist for studying the influence of the sheath. The goal of this study was to develop a method for assessing longitudinal and temporal patterns of sheath influence on flexural stiffness. This metric of flexural stiffness was chosen because it is non-destructive and has been shown to be highly predictive of bending strength. Results: A three-point bending test method was successfully developed for assessing the influence of the sheath on flexural stiffness. The method relies upon comparisons between pairs of tests at the same location (sheath present vs. absent). The influence of the sheath was statistically significant in all varieties tested. The test method provided insights into the longitudinal and spatial variation of sheath influence: sheath influence appears to be closely related to maturity since both spatial and temporal patterns of influence mirror the sigmoidal maturation patterns previously observed in maize stalks. Conclusions: The paired nature of this test method increases statistical significance while the non-destructive feature of this test allows for multiple tests along the length of the stalk. This method can be used to provide new insightsregarding how the leaf sheath influences stalk flexibility (and therefore strength). Preliminary results indicate that the influence of the sheath changes over the life span of the plant in parallel with maturation patterns. However, further studies will be needed to confirm this hypothesis more broadly and to study additional issues such as heritability and the influce of genotype and environment on sheath influence.

Evaluation of Biaxial Bending Strength in Damaged Soda-Lime Glass

2003 ◽  
Vol 17 (08n09) ◽  
pp. 1329-1334 ◽  
Author(s):  
Sang Yeob Oh ◽  
Hyung Seop Shin ◽  
Chang Min Suh
Keyword(s):  
Stress State ◽  
Bending Strength ◽  
Axial Stress ◽  
Brittle Materials ◽  
Soda Lime ◽  
Uniaxial Stress ◽  
Biaxial Stress ◽  
Bending Test ◽  
Ring Test ◽  
Soda Lime Glass

In applications of brittle materials such as soda-lime glass and ceramics, they are usually subjected to a multi-axial stress state. Brittle materials with cracks or damage caused by foreign impacts are apt to fracture abruptly from cracks because of their low fracture toughness. Depending upon the crack pattern developed, the strength using a multi-axial stress state might be different from the one using a uniaxial stress. As a result, when a small size crack was introduced by Vicker's indentation, the residual strength using a biaxial stress state obtained by the ball-on-ring test was greater than that using a uniaxial stress by the 4-point bending test. In the case of the specimens cracked by a spherical impact, there was overall decrease in the bending strength with increasing an impact velocity.

Increase of bending strength and maximum deflection of concrete reinforced with CFRP strips

2011 ◽  
Vol 18 (1-2) ◽  
pp. 93-97
Author(s):  
Goichi Ben ◽  
Kazuhiro Sakata ◽  
Kazuma Saito
Keyword(s):  
High Performance ◽  
Bending Strength ◽  
Concrete Beams ◽  
Beam Theory ◽  
Design Criterion ◽  
Test Method ◽  
Bending Test ◽  
Plastic Behavior ◽  
Four Point Bending ◽  
Miyagi Prefecture

AbstractIn 1981, many detached houses collapsed owing to the earthquake which took place at the coast of Miyagi Prefecture in Japan, because ferroconcrete was not used as the base of most of the collapsed houses. Therefore, the earthquake-proof design criterion was revised and it was obliged to use ferroconcrete as the base of detached houses ever since. However, there are still more than 10 million detached houses using aged concrete as the base in Japan. In this paper, a reinforcement method for the aged concrete is demonstrated by using the high performance carbon fiber reinforced plastic (CFRP) strips. Three kinds of concrete beams reinforced with the CFRP strips with different vertical insert positions and different numbers of the CFRP strips were tested by a four point bending test method. In order to clarify the effects of CFRP strips, a concrete beam without reinforcement was also tested. The results of the experiment showed that the maximum deflections of the concrete beams reinforced with the CFRP strip were more than 100 times larger than those of the concrete beams without reinforcement. Although the concrete beams without the CFRP strips collapsed instantly, the concrete beams reinforced with the CFRP strips gradually failed, which were similar to the plastic behavior of metals. This result means that the residents can afford to escape safely from the houses in the event of possible earthquakes. The experimental results were compared with the analytical ones obtained from the composite beam theory and the failure criterion. Both results showed good agreement and the effectiveness of base concrete reinforced with CFRP strips was demonstrated.

Bending Properties of Five-Layer Biaxial Weft Knitted Fabric Reinforced Composite Materials

2011 ◽  
Vol 391-392 ◽  
pp. 359-363 ◽  
Author(s):  
Wei Geng ◽  
Ye Xiong Qi ◽  
Jia Lu Li
Keyword(s):  
Composite Materials ◽  
Fiber Volume Fraction ◽  
Bending Strength ◽  
Volume Fraction ◽  
Test Method ◽  
Bending Test ◽  
Bending Properties ◽  
Fiber Volume ◽  
Reinforced Composite ◽  
Bending Load

Five-layer biaxial weft knitted (FBWK) fabric is one kind of multilayered biaxial weft knitted (MBWK) fabric. FBWK fabric is made of carbon fiber as inserted yarns and stitched with polyester yarns, and it has been impregnated with epoxy via resin transfer molding (RTM) technique to manufacture the composite plates. The bending properties of the FBWK fabric reinforced composite are studied with the three-point bending test method. The bending properties of the FBWK fabric reinforced composite materials with different fiber volume fraction have been investigated. The results show that the relationship between bending load and deflection is obviously linear before reaching the maximum load. Within a certain range, the bending strength of this kind of composites increases with the fiber volume fraction increasing. When the fiber volume fraction is 57%, the bending strength is 1051.4 MPa.

Evaluation of Impact Bending Strength of Ceramic Composites at Ultra-High Temperatures from 1500-2000 °C in Air

2013 ◽  
Vol 591 ◽  
pp. 145-149 ◽  
Author(s):  
De Tian Wan ◽  
Yi Wang Bao ◽  
Hua Zhao ◽  
Yuan Tian
Keyword(s):  
High Temperatures ◽  
Bending Strength ◽  
Impact Load ◽  
Ceramic Composites ◽  
Test Method ◽  
Bending Test ◽  
Dynamic Force ◽  
Maximal Load ◽  
Impact Bending ◽  
The Impact

In this work, a new and novel test method was developed to determine the impact bending strength of ceramic composites at ultra-high temperature from 1500-2000 °C in air. Three-point impact bending test was carried out through a SiC pressure head with a dynamic force sensor fixed on a slider and movable along a guide rail. The impact load was adjusted by different saving energy and the impact speed was lower than 0.5 m/s. The center of the sample was heated up to about 1500-2000°C by oxygen-assisted spray combustion. An impact load was put on the specimen and the impact force was recorded automatically. The impact bending strength can be calculated from the maximal load and the sample size. To check the availability and reliability for this method, several ceramics including SiC, ZrB2/SiC and C/C fiber reinforced composite without coating, were used as the testing samples. The results indicate that this method is a good and feasible method for evaluating the mechanical properties of the ceramic composite at ultra-high temperatures.

The Resistance Tests of Glass-Cement Plates in High Temperatures

2013 ◽  
Vol 586 ◽  
pp. 182-185
Author(s):  
Michaela Kostelecká ◽  
Miroslav Vokáč ◽  
Daniel Dobiáš
Keyword(s):  
High Temperatures ◽  
Bending Strength ◽  
Precast Concrete ◽  
Point Of View ◽  
Test Method ◽  
Bending Test ◽  
Technical Requirements ◽  
Glass Fibre Reinforced ◽  
Reference Samples ◽  
Strength In Bending

The glass-cement plates have made great progress today. They extend the possibilities of technical requirements in solutions of complex structures. The higher aesthetic requirements are available with the plates and in another point of view they contribute significantly to economic aspect in construction. The article describes the tests of high temperatures resistances of glass-cement plates. The first part is focused on determining the values of tensile strength in bending for samples subjected to annealing at temperatures 200, 300, 400 and 500 ° C in endurance at the highest temperature level for 24 hours. The results will be compared with values obtained for the reference samples. The bending strength was performed according to the norm ČSN EN 1170-4 Precast concrete products - Test method for glass-fibre reinforced cement - Part 4: Measuring bending strength, "Simplified bending test" method. The mean strength in bending of reference samples was equal to 11.3 MPa. The strength is decreasing with temperature of firing and dependence is very closed to linear relationship with slope approx. 1.87 MPa per 100 °C. Furthermore, the thermal dilatometric analysis was performed on the plates in the temperatures till 540 °C in the second part.

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