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Biaxial yield surface investigation of polymer-matrix composites.

Ye J, Qiu Y, Zhai Z, He Z - Sensors (Basel) (2013)

Bottom Line: This article presents a numerical technique for computing the biaxial yield surface of polymer-matrix composites with a given microstructure.On this basis, the manufacturing process thermal residual stress and strain rate effect on the biaxial yield surface of composites are considered.The results show that the effect of thermal residual stress on the biaxial yield response is closely dependent on loading conditions.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Ministry of Education for Electronic Equipment Structure Design, Xidian University, Xi'an 710071, China. ronkey6000@sina.com

ABSTRACT
This article presents a numerical technique for computing the biaxial yield surface of polymer-matrix composites with a given microstructure. Generalized Method of Cells in combination with an Improved Bodner-Partom Viscoplastic model is used to compute the inelastic deformation. The validation of presented model is proved by a fiber Bragg gratings (FBGs) strain test system through uniaxial testing under two different strain rate conditions. On this basis, the manufacturing process thermal residual stress and strain rate effect on the biaxial yield surface of composites are considered. The results show that the effect of thermal residual stress on the biaxial yield response is closely dependent on loading conditions. Moreover, biaxial yield strength tends to increase with the increasing strain rate.

No MeSH data available.


Related in: MedlinePlus

Experimental system of the FBGs strain test system: (a) Picture. (b) Schematic.
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f8-sensors-13-04051: Experimental system of the FBGs strain test system: (a) Picture. (b) Schematic.

Mentions: Figure 8(a,b) shows the picture and schematic of experimental system. The test system is made up of a Fiber Bragg Gratings (FBGs) sensor, composites specimen, material testing system and FBGs demodulation devices. Aluminum alloy tabs of 1 mm thickness were attached to the two ends of the specimen. The elastic modulus, Poisson's ration as well as viscoplastic parameters can be seen in Table 2. To validate the presented model, the uniaxial tensile mechanical responses of 15°, 30°, 45° fiber-reinforced composites with 0.24 fiber volume fraction were measured under two different strain rate (0.00001/s, 0.01/s) conditions. Theoretical results and experimental data are shown in Figure 9. It can be seen that theoretical prediction in different strain rate conditions shows excellent agreement with the experimental results. Comparing Figure 9(a) with Figure 9(b), it can be easily found that increasing strain rate will increase the yield strength of composites under uniaxial tension. For instance, compared with the strain rate 0.00001/s, polymer-matrix composites provide a stress at the 2.5% strain that is approximately 20% higher than the stress of the composites with a strain rate of 0.01/s under 15° fiber off-axis angle conditions.


Biaxial yield surface investigation of polymer-matrix composites.

Ye J, Qiu Y, Zhai Z, He Z - Sensors (Basel) (2013)

Experimental system of the FBGs strain test system: (a) Picture. (b) Schematic.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3673070&req=5

f8-sensors-13-04051: Experimental system of the FBGs strain test system: (a) Picture. (b) Schematic.
Mentions: Figure 8(a,b) shows the picture and schematic of experimental system. The test system is made up of a Fiber Bragg Gratings (FBGs) sensor, composites specimen, material testing system and FBGs demodulation devices. Aluminum alloy tabs of 1 mm thickness were attached to the two ends of the specimen. The elastic modulus, Poisson's ration as well as viscoplastic parameters can be seen in Table 2. To validate the presented model, the uniaxial tensile mechanical responses of 15°, 30°, 45° fiber-reinforced composites with 0.24 fiber volume fraction were measured under two different strain rate (0.00001/s, 0.01/s) conditions. Theoretical results and experimental data are shown in Figure 9. It can be seen that theoretical prediction in different strain rate conditions shows excellent agreement with the experimental results. Comparing Figure 9(a) with Figure 9(b), it can be easily found that increasing strain rate will increase the yield strength of composites under uniaxial tension. For instance, compared with the strain rate 0.00001/s, polymer-matrix composites provide a stress at the 2.5% strain that is approximately 20% higher than the stress of the composites with a strain rate of 0.01/s under 15° fiber off-axis angle conditions.

Bottom Line: This article presents a numerical technique for computing the biaxial yield surface of polymer-matrix composites with a given microstructure.On this basis, the manufacturing process thermal residual stress and strain rate effect on the biaxial yield surface of composites are considered.The results show that the effect of thermal residual stress on the biaxial yield response is closely dependent on loading conditions.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Ministry of Education for Electronic Equipment Structure Design, Xidian University, Xi'an 710071, China. ronkey6000@sina.com

ABSTRACT
This article presents a numerical technique for computing the biaxial yield surface of polymer-matrix composites with a given microstructure. Generalized Method of Cells in combination with an Improved Bodner-Partom Viscoplastic model is used to compute the inelastic deformation. The validation of presented model is proved by a fiber Bragg gratings (FBGs) strain test system through uniaxial testing under two different strain rate conditions. On this basis, the manufacturing process thermal residual stress and strain rate effect on the biaxial yield surface of composites are considered. The results show that the effect of thermal residual stress on the biaxial yield response is closely dependent on loading conditions. Moreover, biaxial yield strength tends to increase with the increasing strain rate.

No MeSH data available.


Related in: MedlinePlus