| 1. |
- Blinzler, Brina, 1987, et al.
(författare)
-
Integrated Computational Material Design for PMC Manufacturing with Trapped Rubber
- 2020
-
Ingår i: Materials. - : MDPI AG. - 1996-1944. ; 13:17
-
Tidskriftsartikel (refereegranskat)abstract
- As the use of continuous fiber polymer matrix composites expands into new fields, there is a growing need for more sustainable manufacturing processes. An integrated computational material design framework has been developed, which enables the design of tailored manufacturing systems for polymer matrix composite materials as a sustainable alternative to achieving high-quality components in high-rate production. Trapped rubber processing achieves high pressures during polymer matrix composite processing, utilizing the thermally induced volume change of a nearly incompressible material inside a closed cavity mold. In this interdisciplinary study, the structural analysis, material science and manufacturing engineering perspectives are all combined to determine the mold mechanics, and the manufacturing process in a cohesive and iterative design loop. This study performs the coupled thermo-mechanical analysis required to simulate the transients involved in composite manufacturing and the results are compared with a previously developed test method. The internal surface pressure and temperatures are computed, compared with the experimental results, and the resulting design process is simulated. Overall, this approach maintains high-quality consolidation during curing while allowing for the possibility for custom distributions of pressures and temperatures. This can lead to more sustainable manufacturing by reducing energy consumption and improving throughput.
|
|
| 2. |
- Khalili, Pooria, 1985, et al.
(författare)
-
Elastomer Characterization Method for Trapped Rubber Processing
- 2020
-
Ingår i: Polymers. - : MDPI AG. - 2073-4360. ; 12:3
-
Tidskriftsartikel (refereegranskat)abstract
- The increasing high-volume demand for polymer matrix composites (PMCs) brings into focus the need for autoclave alternative processing. Trapped rubber processing (TRP) of PMCs is a method capable of achieving high pressures during polymer matrix composite processing by utilizing thermally induced volume change of a nearly incompressible material inside a closed cavity mold. Recent advances in rubber materials and computational technology have made this processing technique more attractive. Elastomers can be doped with nanoparticles to increase thermal conductivity and this can be further tailored for local variations in thermal conductivity for TRP. In addition, recent advances in computer processing allow for simulation of coupled thermomechanical processes for full part modeling. This study presents a method of experimentally characterizing prospective rubber materials. The experiments are designed to characterize the dynamic in situ change in temperature, the dynamic change in volume, and the resulting real-time change in surface pressure. The material characterization is specifically designed to minimize the number and difficulty of experimental tests while fully capturing the rubber behavior for the TRP scenario. The experimental characterization was developed to provide the necessary data for accurate thermomechanical material models of nearly incompressible elastomeric polymers for use in TRP virtual design and optimization.
|
|
| 3. |
- Khalili, Pooria, 1985, et al.
(författare)
-
Ramie fabric Elium® composites with flame retardant coating : Flammability, smoke, viscoelastic and mechanical properties
- 2020
-
Ingår i: Composites. Part A, Applied science and manufacturing. - : Elsevier Ltd. - 1359-835X .- 1878-5840. ; 137
-
Tidskriftsartikel (refereegranskat)abstract
- This investigation studied the utilization of intumescent thermal resistive mats to provide surface protection to the core natural fibre-reinforced Elium® composite structural integrity. The intumescent mats contained flame retardant (FR) i.e. expandable graphite (EG) with four different expansion ratios and alumina trihydrate (ATH). All natural fibre thermoplastic composites were fabricated using a resin infusion technique. The impact of char thickness and chemical compositions on the flammability and smoke properties was investigated. It was found that surface protection significantly reduced the peak heat release rate, total smoke release, smoke extinction area and CO2 yield, and substantially enhanced UL-94 rating, time to ignition and residual char network, depending on the EG exfoliation ratio, ATH and mineral wool fibre. The glass transition temperature increased for the FR composites containing EG with lower expansion ratio. Inclusion of intumescent mats increased the strength of the composites while it had a negative effect on the modulus.
|
|
