Abstract
Composite material has been widely used in various fields for its high specific strength and high specific stiffness, so the connectors applicable to composite structures capture many researchers’ attention. With the advantages of higher carrying capacity and repetitive assembling and disassembling, bolted joint becomes one of the most popular connectors in engineering practice. Cutting off the fiber and causing stress concentration are more serious to composite than metal, so it is necessary to predict the strength of the composite joints. Most investigations focus on the response under quasi-static loading, while dynamic effects should be in consideration in increasing impact conditions. The dynamic mechanical properties of composite joint may have a significant impact on the structural deformation and damage modes. For this purpose, this paper conducts dynamic composite single-bolted joint simulations in ABAQUS/Explicit, which used for predicting dynamic strength of the composite joint. T800/X850 laminates were tested to investigate their dynamic properties in our lab. Then the three-dimension progression damage model was established, while the dynamic constitutive model, damage initial criteria and damage evolution law of composite materials were coded in VUMAT of the finite element software ABAQUS/Explicit. The model was validated by quasi-static experiments of composite joint. The simulation results indicate that the yield strength and ultimate strength of the single-bolted composite joint are obviously increasing when consider the strain rate effect and dynamic loading. And the load-displacement curves show significant difference in damage stage. The main damages are sub-layer buckling and fiber breakage caused by extrusion.
Highlights
Fiber-reinforced composite materials have higher specific strength and specific modulus and good designable performance
A progressive failure model is developed to simulate the failure of composite single-bolted joint, the proposed damage model is applied to a 3D solid element by using ABAQUS/Explicit with
Hashin damage failure criteria consider the four typical failure modes under dynamic loading, including fiber breakage, fiber extrusion, matrix cracking and matrix cracking for in-plane damage of unidirectional laminates
Summary
Fiber-reinforced composite materials have higher specific strength and specific modulus and good designable performance They have been widely used in the defense industry as well as in the fields of construction, chemical engineering and transportation. Ger et al [5] conducted a dynamic tensile test on a carbon fiber/epoxy laminated plate bolt joint They found that the strength of the bolt joint was lower than that under quasi-static load when the loading speed was 5 m/s. Due to differences in test methods, equipment, and data processing methods, as well as differences in properties of composite materials and geometries of bolt joints, the research conclusions on the failure modes, energy absorption, and strain rate effects of joints under dynamic loading are inconsistent. It is necessary to establish an accurate finite element model to analyze the dynamic mechanical properties of the composite bolt joint
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