A DUAL-SCALE MODEL FOR TENSILE PROPERTIES ANALYSIS OF CFRTP-SMC BASED ON MICROPOLAR PERIDYNAMIC METHOD
Topic(s) : Material and Structural Behavior - Simulation & Testing
Co-authors :
Zhiyu WANG (JAPAN), Yi WAN , Jun TAKAHASHI (JAPAN)Abstract :
1 Introduction
The randomly oriented tapes in carbon fiber reinforced thermoplastic sheet molding compounds (CFRTP-SMC) induce a multi-scale structure and high heterogeneity [1] which results in the high scatter of its mechanical properties. Traditional numerical method employing homogeneous model cannot directly reflect the influence from mesoscopic factors on macroscopic mechanical properties of SMC, besides, the constitutive relations expressed in the form of partial differentials in classical continuum mechanics are difficult to handle such discontinuities in SMC.
In this study, a new numerical analysis frame was established to figure out impacts of factors from microscopic and mesoscopic scale on tensile mechanical properties including stiffness, strength, and failure pattern of SMC (fiber breakage, matrix cracking, interlayer debonding). A dual-scale model was proposed to reconstruct the mesoscopic structure of SMC, and a new non-local theory of continuum mechanics [2][3] called the beam-based micropolar peridynamic (MPPD) which has huge advantage in handling discontinue problems and revealing the process of damage, was introduced in numerical tensile simulation of SMC.
2.Methods
2.1 Dual-scale CFRTP-SMC Model
The dual-scale model consists of microscopic and mesoscopic part. In the microscopic scale, the X-ray scanner is used to determine the fiber orientation distribution (FOD). In the mesoscopic scale, a random fiber tape reconstruction algorithm is developed to generate a mesostructured model. And the improved random sequential adsorption (RSA) [5] method considering tape overlapping effect is used during the modeling generation.
2.2 SMC MMPD model based on Timoshenko beam
To show the heterogeneity of SMC, the MMPD model based on Timoshenko beam for orthotropic material was derived and utilized as the single tape model. Furthermore, two types of bonds reflecting intralayer and interlayer effect were derived. The previous dual-scale model as the input parameter of the MMPD model. Since the failure of SMC is a mixed failure mode in which interlayer debonding dominates, three different damage criteria were applied to fiber, matrix, and interlayer respectively.
In the numerical implementation, a new GPU parallel scheme based on CUDA was utilized to accelerate the numerical simulation of PD model to achieve significant time efficiency.
3 Results
In the numerical model, we first simulated the tensile simulation of SMC with different tape sizes under real FOD and fiber volume distribution, and compared the stiffness and strength results with experiment results [6]. Then the values of fiber orientation tensor and fiber volume distribution were changed to explore their impact on the tensile stiffness and strength of SMC.
Secondly, through the damage plots obtained in the tensile simulation, the failure patterns of SMC with different sizes, FOD and fiber volume fraction has been analyzed, and compared the results with experiment results.
The randomly oriented tapes in carbon fiber reinforced thermoplastic sheet molding compounds (CFRTP-SMC) induce a multi-scale structure and high heterogeneity [1] which results in the high scatter of its mechanical properties. Traditional numerical method employing homogeneous model cannot directly reflect the influence from mesoscopic factors on macroscopic mechanical properties of SMC, besides, the constitutive relations expressed in the form of partial differentials in classical continuum mechanics are difficult to handle such discontinuities in SMC.
In this study, a new numerical analysis frame was established to figure out impacts of factors from microscopic and mesoscopic scale on tensile mechanical properties including stiffness, strength, and failure pattern of SMC (fiber breakage, matrix cracking, interlayer debonding). A dual-scale model was proposed to reconstruct the mesoscopic structure of SMC, and a new non-local theory of continuum mechanics [2][3] called the beam-based micropolar peridynamic (MPPD) which has huge advantage in handling discontinue problems and revealing the process of damage, was introduced in numerical tensile simulation of SMC.
2.Methods
2.1 Dual-scale CFRTP-SMC Model
The dual-scale model consists of microscopic and mesoscopic part. In the microscopic scale, the X-ray scanner is used to determine the fiber orientation distribution (FOD). In the mesoscopic scale, a random fiber tape reconstruction algorithm is developed to generate a mesostructured model. And the improved random sequential adsorption (RSA) [5] method considering tape overlapping effect is used during the modeling generation.
2.2 SMC MMPD model based on Timoshenko beam
To show the heterogeneity of SMC, the MMPD model based on Timoshenko beam for orthotropic material was derived and utilized as the single tape model. Furthermore, two types of bonds reflecting intralayer and interlayer effect were derived. The previous dual-scale model as the input parameter of the MMPD model. Since the failure of SMC is a mixed failure mode in which interlayer debonding dominates, three different damage criteria were applied to fiber, matrix, and interlayer respectively.
In the numerical implementation, a new GPU parallel scheme based on CUDA was utilized to accelerate the numerical simulation of PD model to achieve significant time efficiency.
3 Results
In the numerical model, we first simulated the tensile simulation of SMC with different tape sizes under real FOD and fiber volume distribution, and compared the stiffness and strength results with experiment results [6]. Then the values of fiber orientation tensor and fiber volume distribution were changed to explore their impact on the tensile stiffness and strength of SMC.
Secondly, through the damage plots obtained in the tensile simulation, the failure patterns of SMC with different sizes, FOD and fiber volume fraction has been analyzed, and compared the results with experiment results.