Drop-Weight Impact Responses of Woven Hybrid Glass-Graphite/Toughened Epoxy Composites

2008 ◽  
Author(s):  
E. Sevkat ◽  
B. M. Liaw ◽  
F. Delale ◽  
B. B. Raju
Keyword(s):  
Finite Element ◽  
Nonlinear Finite Element ◽  
Dynamic Force ◽  
Composite Panels ◽  
Finite Element Software ◽  
Impact Tests ◽  
Toughened Epoxy ◽  
Drop Weight ◽  
Different Shapes ◽  
Weight Impact

A hybrid experimental and 3-D dynamic nonlinear finite element approach was used to study damage in 101.6mm × 101.6mm composite panels subject to drop-weight impact up to 50 J. The specimens tested were made of hybrid woven S2-glass-IM7 graphite fibers/toughened epoxy (cured at 177°C). The composite panels were damaged by impacts using a pressure-assisted Instron-Dynatup 8520 instrumented drop-weight impact tester. During the low velocity impact tests, the time-histories of impact-induced dynamic strains and impact forces were recorded. Two types of drop-weight impact tests were conducted. The first focused on the effect of different shapes of the impactor and the second involved progression of the damage in the composite when impacted repeatedly. The commercially available 3-D dynamic nonlinear finite element software, DYNA, was then used to simulate the experimental results of drop-weight tests using different shapes of the impactor. Good agreement between experimental and FEM results has been achieved when comparing dynamic force, strain histories and damage patterns from experimental measurements and finite element simulations.

Temperature Effect on Drop-Weight Impact of Hybrid Woven Composites

2010 ◽  
Author(s):  
Yougashwar Budhoo ◽  
Benjamin Liaw ◽  
Feridun Delale ◽  
Ramki Iyer
Keyword(s):  
Finite Element ◽  
Hybrid Composites ◽  
Damage Model ◽  
Woven Composites ◽  
Effect Of Temperature ◽  
Composite Panels ◽  
Finite Element Software ◽  
Dynamic Finite Element ◽  
Drop Weight ◽  
Weight Impact

This paper investigates the effect of temperature on hybrid and non-hybrid woven composite panels (100mm×100mm×6.35mm) drop-weight impacted at five different temperatures:−60°C,−20°C, room temperature (R.T), 75°C and 125°C. The studies were conducted by combining experimental and 3-D dynamic finite element (FE) approaches. The specimens tested were made of plain-weave hybrid S2 glass-IM7graphite fibers/toughened epoxy. The composite panels were damaged using an instrumented drop-weight impact tester equipped with an environmental chamber for temperature control. The time-histories of impact-induced dynamic strains and impact forces were recorded. The damaged specimens were inspected visually and using the ultrasonic C-scan method. A 3-D dynamic finite element software package, with Chang-Chang composite damage model, was then used to simulate the experimental results of the drop-weight tests. Good agreement between experimental and FE results has been achieved. It is observed that the variation of results obtained from our experiments for the hybrid composites was very small (about 8%) when compared to those of non-hybrid composites. Also, when looking at the hybrid or non-hybrid composite, the effect of temperature at −60°C, −20°C was not significant whereas at 75°C and 125°C the results were more distinct.

Experimental and Numerical Studies of S2-Glass Fiber/Toughened Epoxy Composite Beams Subject to Drop-Weight or Ballistic Impact

2007 ◽  
Author(s):  
E. Sevkat ◽  
B. M. Liaw ◽  
F. Delale ◽  
B. B. Raju
Keyword(s):  
Finite Element ◽  
Impact Force ◽  
Damage Model ◽  
Composite Beams ◽  
Ballistic Impact ◽  
Nonlinear Finite Element ◽  
Experimental Results ◽  
Anisotropic Damage ◽  
Drop Weight ◽  
Weight Impact

A combined experimental and 3-D dynamic nonlinear finite element approach was adopted to study composite beams subject to drop-weight or ballistic impact. The composite specimens, made of S2 glass-reinforced toughened epoxy (44% fiber volume fraction, cured at 350°F), had 24 layers (approximately 6.35 mm) with various stacking sequences. They were damaged by impacts using either an Instron-Dynatup 8520 instrumented drop-weight impact tester (low-velocity impact) or an in-house high-speed gas gun (ballistic impact). For both types of tests, the time-histories of dynamic strains induced during impact were recorded using strain gages mounted on the front and back of the composite beam specimen. For drop-weight impact tests, the time history of impact force was also recorded; whereas for ballistic impact tests, only the impact velocity was calculated from the recorded change in voltage outputs, which resulted from the traversing of the impactor through two optical paths formed by two sets of diode laser-amplified photo diode pairs. The commercially available 3-D dynamic nonlinear finite element software, LS-DYNA, incorporated with a proposed nonlinear anisotropic damage model, was then used to simulate the experimental results. Good agreement between experimental and FEM results can be seen from comparisons of dynamic strain and impact force histories and damage patterns. Once the proposed nonlinear anisotropic damage model was verified by experimental results, further finite element simulations were conducted to predict the ballistic limit velocity (V50) for penetration prevention.

Research on the Numerical Simulation of Hot Stamping for High Strength Steel

2014 ◽  
Vol 898 ◽  
pp. 136-139
Author(s):  
Chang Feng Men ◽  
Wen Wen Du ◽  
Cui Hong Han
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
High Strength Steel ◽  
Hot Stamping ◽  
High Strength ◽  
Nonlinear Finite Element ◽  
Weight Percentage ◽  
Finite Element Software ◽  
Simulation Results ◽  
Die Temperature

In order to research on the hot stamping property of high strength steel, the stamping forming of USIBOR1500P is simulated by the nonlinear finite element software Dynaform and Ansys/ls-dyna. The initial data simulated on USIBOR1500P is obtained by the hot tensile test. The simulation results show that the martensite weight percentage and Vickers hardness are in inverse proportion to stamping speed and initial die temperature.

Finite Element Simulation and Experiment of Mechanical Expanding for Longitudinal Welded Pipe

2015 ◽  
Vol 727-728 ◽  
pp. 493-496
Author(s):  
Yun Feng Yao ◽  
Ying Gao ◽  
Jun Xia Li ◽  
Shuang Jie Zhang ◽  
Tao Han
Keyword(s):  
Finite Element ◽  
Simulation Model ◽  
Finite Element Simulation ◽  
Nonlinear Finite Element ◽  
Two Dimensional ◽  
Finite Element Software ◽  
Element Simulation ◽  
Dimensional Finite Element ◽  
Simulation And Experiment ◽  
Welded Pipe

A two-dimensional finite element simulation model of longitudinal welded pipe is established by the nonlinear finite element software ABAQUS. Testing enlargement mould is used for the expanding experiments for the welded pipe under the laboratory condition. The expanding force, ovality and the shape are simulated and measured. Comparing the experimental and the simulated results, the values are fitted well.

Finite Element Analysis of Earthquake Resistance Behaviors of T-Shaped Concrete-Filled Rectangular Composite Steel Tubular Columns

2014 ◽  
Vol 501-504 ◽  
pp. 1633-1638
Author(s):  
Jun Huang ◽  
Yi Chao Zhang ◽  
Shao Bin Dai
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bearing Capacity ◽  
Fem Analysis ◽  
Nonlinear Finite Element ◽  
Earthquake Resistance ◽  
Element Analysis ◽  
Tubular Columns ◽  
Finite Element Software ◽  
Composite Steel

By using finite element software ABAQUS, the nonlinear finite element analysis of earthquake resistance behavior of T-shaped concrete-filled rectangular composite steel tubular columns is carried out, furthermore, the analysis results and the corresponding experiment results are compared. The results indicate that the calculated value of ultimate bearing capacity is less than the experimental value, and the results of FEM analysis can match the experiment results better, and thus, it can better reflect the earthquake resistance behaviors of the specimens.

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