- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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A poly (vinyl butyral)/graphene oxide composite with NIR light-induced shape memory effect and solid-state plasticity
摘要： A NIR light-induced shape memory composite with light-induced plasticity was prepared by incorporating graphene oxide (GO) into cross-linked poly (vinyl butyral) (PVB). The cross-linked reaction between PVB and aromatic diisocyanate not only endowed the composites with excellent shape memory properties, but also offered the performance of solid-state plasticity due to the formation of carbamate bonds. The photo-responsive performance was introduced to the system by doping GO, a conventional photothermal reagent, resulting in excellent NIR light-induced shape memory properties and light-induced plasticity. According to the stress relaxation tests, the solid-state plasticity of composites could be regulated by the cross-linked density, GO, catalyst dosage and temperature. Moreover, the composites can be repeatedly programmed to a new permanent shape via a light-induced plasticity process, which still exhibited excellent light-induced shape memory properties even after 5 cycles of reconfiguration. The results demonstrate the promising prospect of these composites as actuator elements for applications in self-deployment devices and soft robotic.
关键词： Smart materials,Functional composites,Shape memory polymers,Polymer-matrix composites (PMCs),Plastic deformation
更新于2025-09-23 15:21:21
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Intimate contact development during laser assisted fiber placement: Microstructure and effect of process parameters
摘要： Intimate contact development under LAFP-specific thermal and mechanical boundary conditions/interactions and the effect of process parameters are investigated. One-layer, unidirectional strips of CF/PEKK material were placed with different process parameters on a flat tool surface to create different intimate contact conditions. The concept of effective intimate contact, which is based on the resin content at the surface, is introduced and a methodology to measure it from surface micrographs is provided. Degree of effective intimate contact measured from the samples was compared with the existing intimate contact models. The temperature history in the compaction zone was estimated with a finite element model and pressure sensitive films were used to determine the compaction pressure. It is shown that in addition to the squeeze flow mechanism, which is the base for the current intimate contact models, through-thickness percolation flow of the resin needs to be considered to explain the effective intimate contact development.
关键词： B. Microstructures,C. Process modeling,E. Automated fiber placement (AFP),A. Polymer-matrix composites (PMCs)
更新于2025-09-23 15:21:01
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Effect of long-term mechanical cycling and laser surface treatment on piezoresistive properties of SEBS-CNTs composites
摘要： The piezoresistive behaviour of SEBS-CNTs nanocomposites was investigated to evaluate their potential applications as strain sensors. Composites containing from 3%wt. to 7%wt. of CNTs were processed by injection moulding in order to evaluate the percolation threshold. The piezoresistive response under flexural strain of nanocomposites with a CNTs content above the percolation threshold was then studied. The nanocomposites showing the most promising performance were tested under cyclic conditions. Conductive tracks were then processed on nanocomposites surfaces (with 3 and 4% of CNTs) by means of a laser treatment. Samples with optimized laser tracks were then submitted to 1000 stretching/releasing cycles, showing improved piezoresistive performance.
关键词： Piezoresistive behaviour,Polymer-matrix composites (PMCs),Surface treatment,Electrical properties
更新于2025-09-23 15:19:57
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Laser treatment surface: An innovative method to increase the adhesive bonding of ENF joints in CFRP
摘要： Recently, many studies showed the opportunity to use a CO2 laser for treating the surfaces for structural bonding. In this work, a study on the effectiveness of a laser texturing on ENF bonded joints made with CFRP and epoxy adhesive has been developed. The experimental results showed that the use of this technology allows obtaining mechanical resistances of the bonded joints higher than 80% compared to untreated ones. Furthermore, a numerical model is proposed to forecast the response of the ENF specimens, and the numerical results are in good agreement with the experimental ones. This work represents a basis for the development of an innovative approach to design the laser texturing as a function of the applied stress.
关键词： A. Adhesive joints,C. Finite element analysis (FEA),A. Polymer-matrix composites (PMCs),B. Surface treatments,B. Debonding
更新于2025-09-12 10:27:22