Numerical Modeling of Damage Caused by Seawater Exposure on Mechanical Strength in Fiber-Reinforced Polymer Composites

Abstract

Fiber-reinforced polymer composites are frequently used in marine environments which may limit their durability. The development of accurate engineering tools capable of simulating the effect of seawater on material strength can improve design and reduce structural costs. This paper presents a numerical-based approach to predict the stress–strain response of fiber-reinforced polymer composites exposed to different seawater immersion times, ranging from 0 to 900 days. A three-dimensional numerical model has been implemented using a static implicit finite element analysis along with a user-defined material (UMAT) subroutine. Puck’s failure criterion was used for ultimate failure analysis of the laminates, while Fick’s first diffusion law was used to predict the seawater absorption rate. Overall, the simulated stress–strain curves were close to those obtained experimentally. Moreover, the model agreed well with the experimental data regarding the maximum stress and the strain at failure leading to maximum errors lower than 9% and 11%, respectively. Additionally, the simulated strain fields agreed well with the experimental results measured by digital image correlation. Finally, the proposed procedure was also used to identify the most critical surfaces to protect the mechanical components from marine environments.

Development of an Fe3O4 Surface-Grafted Carboxymethyl Chitosan Molecularly Imprinted Polymer for Specific Recognition and Sustained Release of Salidroside

“…Template molecules can play a role in determining the particle size and surface m phology of the final MIP products [29,30]. Compared with SMCNIP, the surface ro ness of SMCMIPs could be due to the imprinting of the template molecules, leading…”

“…Template molecules can play a role in determining the particle size and surface morphology of the final MIP products [29,30]. Compared with SMCNIP, the surface roughness of SMCMIPs could be due to the imprinting of the template molecules, leading to a higher specific surface area, improved stability, and higher selectivity for the target analyte (Figure 5).…”

“…Fick proposed that the flow of diffusion material through the unit cross-sectional area perpendicular to the diffusion direction in unit time is proportional to the concentration gradient at that section; that is, the greater the concentration gradient, the greater the diffusion flux. According to Fick's first law [30], the diffusion coefficients of SMCMIP ranged from 3.07 × 10 −2 cm 2 /s to 5.66 × 10 −3 cm 2 /s. Depending on the ratio of SMCMIP and SMCNIP diameters to the thickness and the spherical structure with an uneven particle size distribution, n was correlated with the release index.…”