Test methods for fibre-reinforced cementitious composites - Bending moment - Curvature curve by four-point bending test

2019 ◽  
Keyword(s):  
Bending Moment ◽  
Test Methods ◽  
Bending Test ◽  
Cementitious Composites ◽  
Four Point Bending ◽  
Four Point Bending Test

Test Methods for Silicon Die Strength

2006 ◽  
Vol 128 (4) ◽  
pp. 419-426 ◽  
Author(s):  
M. Y. Tsai ◽  
C. H. Chen ◽  
C. S. Lin
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Test Methods ◽  
Biaxial Stress ◽  
Bending Test ◽  
Published Data ◽  
Failure Strength ◽  
Surface Conditions ◽  
Four Point Bending ◽  
Four Point Bending Test

Recently, the 3D or stacked-die packages become increasingly popular for packaging ICs into a system or subsystem to satisfy the needs of low cost, small form factor, and high performance. For the applications of these packages, IC silicon wafers have to be ground to be relatively thin through the wafer-thinning processes (such as grinding, polishing, and plasma etching). The strength of dies has to be determined for the design requirement and reliability assurance of the packages. From the published data, there still exist some issues, including a large scatter existed in die strength data and difficulties in differentiating the causes of the low strength between from the wafer grinding and from wafer sawing by either the three-point bending or four-point bending test. The purposes of this study are to develop new, reliable, and simple test methods for determination of die strength, in order to improve the data scatter, and to provide a solution for differentiating the factors that affect the variability of die strength for finding out the causes of the weakness of the die strength. In this study, two new test methods, point-loaded circular plate with simple supports test (PLT-I) and point-loaded plate on elastic foundation test (PLT-II), are proposed and then evaluated by testing two groups of silicon dies with different surface conditions. The surface conditions (roughness) of the specimens are determined by atomic force microscopy and correlated to failure strength. The failure forces from both tests have to be modified by using maximum stress obtained from theories or finite element analyses to obtain the failure strength. The test results are compared to each other and further with a widely used four-point bending test. The results suggest that, unlike the four-point bending test suffering the chipping effect, both methods provide very consistent data with a small scatter for each group of specimens and can be used for identifying the effect of surface grinding (roughness) on the die strength. It is also shown that the die strength is highly dependent on the surface roughness. Accordingly, these two methods can provide not only a (biaxial) stress field similar to temperature-loaded die in the packages, but also simple, feasible, reliable, and chipping-free tests for silicon dies of dummy or real IC chips, without strict geometrical limitation, such as beam-type geometry for the three-point or four-point bending test.

scholarly journals Comparison of the two point bending and four point bending test methods for aged asphalt concrete field samples

2014 ◽  
Vol 48 (9) ◽  
pp. 2901-2913 ◽  
Author(s):  
Lily D. Poulikakos ◽  
Michel Pittet ◽  
Andre-Gilles Dumont ◽  
Manfred N. Partl
Keyword(s):  
Asphalt Concrete ◽  
Test Methods ◽  
Bending Test ◽  
Four Point Bending ◽  
Field Samples ◽  
Aged Asphalt ◽  
Four Point Bending Test

An Analysis of the Local Buckling Collapse Behavior of an Aluminum Square Tube under Concentrated Bending Moment Loads

2004 ◽  
Vol 261-263 ◽  
pp. 633-638 ◽  
Author(s):  
Sung Hyuk Lee ◽  
Nak Sam Choi
Keyword(s):  
Finite Element ◽  
Local Buckling ◽  
Bending Moment ◽  
Bending Test ◽  
Aluminum Tube ◽  
Four Point Bending ◽  
Element Simulation ◽  
Steel Bars ◽  
Four Point Bending Test ◽  
Collapse Behavior

To analyze the bending collapse behavior of an aluminum square tube under the bending moment load, a finite element simulation for the four-point bending test has been performed. Using an aluminum tube beam specimen partly inserted with two steel bars, local buckling deformation near the center of the tube beam was induced. Simulated moment-rotation angle curve obtained during the post-collapse period of the aluminum tube with steel bars were in good agreement with experimental result, which was comparable to the result obtained from Kecman's theory. Using a combination of the four-point bending test and its finite-element simulation, analysis of the local buckling and the bending collapse behavior of an aluminum tube beam could be quantitatively accomplished.

Novel Test Methods for Die Strength

2005 ◽  
Author(s):  
M. Y. Tsai ◽  
C. H. Chen ◽  
C. S. Lin
Keyword(s):  
High Performance ◽  
Axial Stress ◽  
Test Methods ◽  
Bending Test ◽  
Published Data ◽  
Failure Strength ◽  
Element Analysis ◽  
Surface Conditions ◽  
Four Point Bending ◽  
Four Point Bending Test

Recently, the 3-D or stacked-die packages are increasingly popular for packaging ICs into a system or subsystem to satisfy the needs of low cost, small form factor, and high performance. For the applications of these packages, IC wafers have to be ground to be relatively thin through the wafers thinning processes (such as grinding, polishing, and plasma etching). The strength of dies has to be determined for the design requirement and thus assuring reliability of the packages. From the published data, there still exist some issues including a large scatter existed in die strength data, and difficulties with differentiating the causes of the low strength from the grinding or die sawing either by three-point bending or four-point bending test. The purposes of this study is to develop new, reliable and simple test methods for determination of die strength to improve the data scatter and also provide a solution for differentiating the factors that affect the variability of die strength, in order to find out the causes of the weakness of the die strength. In this study, two new test methods, point-loaded circular plate with simple supports test (PLT-I) and point-loaded plate on elastic foundation test (PLT-II) are proposed and evaluated by testing two groups of silicon dies with different surface conditions. The surface conditions (roughness) of the specimens are determined by atomic force microscopy and correlated to failure strength. The failure forces from both tests have to be modified by using maximum stress obtained from theory or finite element analysis to get the failure strength. The test results are compared with each other and further with widely-used four-point bending test. The results suggest that, unlike the four-point bending test, both methods provide very consistent data with a small scatter for these two groups of specimens, and indicated the die strength is highly dependent on the surface roughness. Accordingly, these two methods can provide not only a (bi-axial) stress field similar to temperature-loaded die in the packages, but also simple, feasible, reliable and chipping-free tests for silicon dies of dummy or real IC chips, without strict geometrical limitation, such as beam-type geometry for three-point or four-point bending test.

Comparison of a standardized four-point bending test to an implant system test of an osteosynthetic system under static and dynamic load condition

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Christian Halbauer ◽  
Hendrik Schorler ◽  
Laura Liberto ◽  
Felix Capanni
Keyword(s):  
Load Condition ◽  
Bending Moment ◽  
Secondary Phase ◽  
Mechanical Analysis ◽  
Test Method ◽  
Bone Plate ◽  
Bending Test ◽  
Four Point Bending ◽  
Four Point Bending Test ◽  
Implant System

Abstract Current test standards of osteosynthetic implants examine the bone plate and screw separately leading to unrealistic load scenarios and unknown performance of the system as a whole, which prevents the identification of characteristic failures in clinical use. A standardized static and dynamic four-point bending test (ASTM F382) was performed on a bone plate. Based on that standard, an advanced implant system test (IST) was designed and performed to test a mechanical construct consisting of a bone plate, screws and an artificial bone substitute out of Polyoxymethylene (POM). The test object was an osteosynthetic system to treat fractured ulna bones. Both results of the conventional and advanced test method were analyzed and compared to one another. The static results show a similar yield point (YP) relative to the bending moment with just 9% difference. Dynamic results show a bi-phasic behavior of the displacement vs. cycle data for the IST. The secondary phase can be defined as a constantly increasing plastic deflection or ratcheting effect quantified by its slope in mm per one million cycles, leading to a 10 times higher slope for the IST than the conventional test. The IST has a high impact on the test results and the resultant interpretation of the mechanical behavior of the osteosynthetic system. A constantly increasing plastic deflection might lead to fatigue failures and to a loss of the mechanical durability. The development of new standardizations referring to the whole system within reasonable boundary conditions of individual biomechanical applications is crucial for high quality mechanical analysis.

scholarly journals Structural behaviour of PSCC slab panel under four-point bending test

2021 ◽  
Vol 1144 (1) ◽  
pp. 012039
Author(s):  
M A Iman ◽  
N Mohamad ◽  
A A A Samad ◽  
Steafenie George ◽  
M A Tambichik ◽  
...  
Keyword(s):  
Bending Test ◽  
Structural Behaviour ◽  
Four Point Bending ◽  
Four Point Bending Test

Manufacturing a carbon/epoxy NACA 23018 airfoil skin using a circular braiding machine: experimental and numerical study

2021 ◽  
pp. 152808372199377
Author(s):  
Jalil Hajrasouliha ◽  
Mohammad Sheikhzadeh
Keyword(s):  
Numerical Study ◽  
Filament Winding ◽  
Bending Test ◽  
Elastic Response ◽  
Manufacturing Processes ◽  
Fiber Reinforced Composite ◽  
Four Point Bending ◽  
Reinforced Composite ◽  
Four Point Bending Test ◽  
Meso Scale

In the interest of reducing the weight and also cost of blade skins, various automatic preform manufacturing processes were developed including tape laying, filament winding and braiding. Among them, the circular braiding process was found to be an efficient method in producing seamless preforms on mandrels with various geometries. In this regard, an attempt was made to produce a carbon fiber reinforced composite with the shape of NACA 23018 airfoil using a circular braiding machine. Thus, suitable wooden mandrels were manufactured using NACA 23018 airfoil coordinates, which were obtained by assuming the perimeter of 20 cm. Furthermore, both biaxially and triaxially braided preforms were produced and subsequently impregnated with epoxy resin through an appropriate fabrication method. To assess their performance, four-point bending test was carried out on samples. Ultimately, the elastic response of braided composite airfoils was predicted using a meso-scale finite element modeling and was validated with experimental results.

Sign in / Sign up

Export Citation Format

Share Document