![]() Consequently, they are often over-engineered to prevent failure. Traditional synthetic material systems, on the other hand, lack the ability to self-repair. Bereft of in situ and sustained repair, a benign cut could exacerbate and prove fatal. For instance, upon laceration in healthy human skin, healing begins instantly and continues until restoring necrotic with new tissue-without hindering other body functionalities 2. (ii) Sustained: the healing functionality persists even after many damage/repair cycles (i.e., throughout an organism’s life). The success of biological healing stems from two essential attributes: (i) In situ: an innate capacity to deliver healing agents to the injured site and self-repair the damage in place. The ability to heal and recover from minor injuries is vital for living organisms 1. The marked lifetime extension offered by this self-healing strategy mitigates costly maintenance, facilitates repair of difficult-to-access structures (e.g., wind-turbine blades), and reduces part replacement, thereby benefiting economy and environment. A discovery of chemically driven improvement in thermal remending of glass- over carbon-fiber composites is also revealed. Full fracture recovery occurs below the glass-transition temperature of the thermoset epoxy-matrix composite, thus preserving stiffness during and after repair. By 3D printing a mendable thermoplastic onto woven glass/carbon fiber reinforcement and co-laminating with electrically resistive heater interlayers, we achieve in situ thermal remending of internal delamination via dynamic bond re-association. Here we transcend existing obstacles and report a fiber-composite capable of minute-scale and prolonged in situ healing - 100 cycles: an order of magnitude higher than prior studies. Overcoming these inherent challenges for mechanical self-recovery is vital to extend in-service operation and attain widespread adoption of such bioinspired structural materials. ![]() But sustained in-service repair of structural fiber-reinforced composites remains unfulfilled due to material heterogeneity and thermodynamic barriers in commonly cross-linked polymer-matrix constituents. An emerging class of synthetic self-healing polymers and composites possess property-retaining functions with the promise of longer lifetimes. Furthermore, it is demonstrated that a loose ply stack up is more amenable to the production of high-quality preforms than a preconsolidated charge of material.Natural processes continuously degrade a material’s performance throughout its life cycle. Undesirable wrinkling that manifests during deep-drawing of the material is found to be most effectively mitigated through the use of sufficient binder pressure. Forming trials are conducted on Dyneema ® HB80, a cross-ply thermoplastic lamina, using a laboratory deep-draw setup to explore the effects of processing parameters on the quality of the formed part. An overview of current fabrication procedures is provided in addition to a discussion of the material selection and preform processing technique. To accomplish these objectives, near-net-shape preforming is explored as an alternative method to the traditional cut and dart techniques used in the manufacture of combat helmets. The research efforts presented in this paper focus on improving the ballistic performance of composite combat helmets through the control of fiber orientations, reduction of seam density, and preservation of long fiber lengths. With the evolution of modern warfare, there is a constant demand for enhanced soldier protection. Journal of Verification, Validation and Uncertainty Quantification.Journal of Thermal Science and Engineering Applications.Journal of Offshore Mechanics and Arctic Engineering.Journal of Nuclear Engineering and Radiation Science.Journal of Nondestructive Evaluation, Diagnostics and Prognostics of Engineering Systems.Journal of Nanotechnology in Engineering and Medicine.Journal of Micro and Nano-Manufacturing. ![]()
0 Comments
Leave a Reply. |