Microstructure modeling multiple transverse impact damages of 3-D braided composite based on thermo-mechanical coupling approach

Abstract This paper presents a new three-dimensional thermo-mechanical (TM) coupling approach for thermal fracturing of rocks in the finite–discrete element method (FDEM). The linear thermal expansion formula is implemented in the context of FDEM according to the concept of the multiplicative split of the deformation gradient. The presented TM formulation is derived in the geo-mechanical solver, enabling thermal expansion and thermally induced fracturing. This TM approach is validated against analytical solutions of the Cauchy stress, thermal expansion and stress distribution. Additionally, the thermal load on the previously validated configurations is increased and the resulting fracture initiation and propagation are observed. Finally, simulation results of the cracking of a reinforced concrete structure under thermal stress are compared to experimental results. Results are in excellent agreement.

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Micro-XCT analysis of damage mechanisms in 3D circular braided composite tubes under transverse impact

Composites Science and Technology ◽

10.1016/j.compscitech.2017.11.025 ◽

2018 ◽

Vol 155 ◽

pp. 91-99 ◽

Cited By ~ 20

Author(s):

Haili Zhou ◽

Chao Li ◽

Liquan Zhang ◽

Bryn Crawford ◽

Abbas S. Milani ◽

...

Keyword(s):

Transverse Impact ◽

Composite Tubes ◽

Damage Mechanisms ◽

Braided Composite

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Multiple transverse impact damage behaviors of 3-D-braided composite beams under room and high temperatures

International Journal of Damage Mechanics ◽

10.1177/1056789519867434 ◽

2019 ◽

Vol 29 (5) ◽

pp. 715-747

Author(s):

Meiqi Hu ◽

Shengkai Liu ◽

Junjie Zhang ◽

Lei Wang ◽

Baozhong Sun ◽

...

Keyword(s):

Elevated Temperatures ◽

Impact Damage ◽

Three Dimensional ◽

Composite Beams ◽

Transverse Impact ◽

Engineering Structure ◽

Braided Composite ◽

Impact Deformation ◽

Initial Modulus ◽

The Impact

Three-dimensional braided composite materials have been widely applied to engineering structure manufacturing. It is of a great importance to characterize the impact damage of the three-dimensional braided composite under various temperatures for optimizing the engineering structure. Here we conducted transverse impact deformation and damage of three-dimensional braided composite beams with different braiding angles at room and elevated temperatures. A split Hopkinson pressure bar with a heating device combined with high-speed camera was employed to test multiple transverse impact behaviors and to record the impact deformation developments. The results indicated that failure load, initial modulus, and energy absorption decreased with the increase of temperature, whereas the deformation increased slightly with elevated temperatures. We found that the impact brittle damages occurred earlier and the local adiabatic temperature raised higher when the temperature is lower than the glass transition temperature (Tg) of epoxy resin. While above the Tg, the impact ductile damages occurred later and the local temperature raised lower. The thermal stress distribution along the braiding yarn leads to cracks propagation in yarn direction. Part of the impact energy absorptions converted into thermal energy. In addition, the beam with larger braiding angle has high damage tolerance and crack propagation resistance.

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