Effects of Subzero Temperatures and Sea Water Immersion on Damage Initiation and Growth in Sandwich Composites

2008 ◽  
Author(s):  
Barry D. Davidson
2018 ◽  
Vol 53 (21) ◽  
pp. 3033-3045 ◽  
Author(s):  
MA Abd El-baky ◽  
MA Attia

The main objective of the present paper is to study the water absorption of jute–glass–carbon-reinforced epoxy composites and its subsequent effect on the in-plane shear performance of these composites. The effects of the reinforcement hybridization, stacking sequence and relative fabric amounts on the shear behavior of dry and wet conditioned composite specimens are reported and discussed. Composites have been fabricated in inter-ply configuration using the hand lay-up process. The prepared specimens have been subjected to distilled water and sea water immersion at room temperature for 60 days. Results indicated that water uptake of jute-reinforced composite and its hybrids with glass and/or carbon follows Fickian-like behavior. Water uptake induces a significant decrease in the in-plane shear strength. Hybridizing jute fabric with glass and/or carbon fabrics improves the in-plane shear properties of both dry and wet specimens. The stacking sequence and relative fabric amounts have a noticeable effect on the studied shear properties. Also, the hybrid composite with jute as facings and glass as core, JGJ, offers the most balanced set of properties on a cost-effective basis compared to the other studied hybrids.


Environments ◽  
2019 ◽  
Vol 6 (9) ◽  
pp. 103
Author(s):  
Stoyan Vergiev

Integrated coastal zone management proposes nature-based mitigation strategies based on the replacement of artificial coastal stabilization and protection structures with dunes stabilized with plant species. These psammophytes stabilize sands and act as supporters, increasing dunes’ ability to reduce storm damages and effectively minimize erosion with minimal negative impacts to natural ecosystems. That is why searching for native salt-tolerant plants with extensive root systems and studying their capacity for erosion and flooding control is fundamental to the practice of ecologically-sound ecosystem services. The aim of the present study is to define the effects of flooding stress on a number of wheatgrass (Thinopyrum ponticum) plant life aspects (survival ability, viability, and growth response) in order to determine wheatgrass’s capacity as dune stabilizer. Conducted experiments established that T. ponticum was very tolerant to immersion impact and salt and oxygen deficiency stress, and its rhizomes were able to regenerate after 30 days in seawater. The temporal expression of its survival is presented as critical decomposition time (CDT) by linking the maximum duration of floods along the Bulgarian Black Sea Coast and the resilience of tall wheatgrass in flooding simulations. A statistical analysis of the experimental data demonstrated that immersion in sea water increases rhizome viability, biomass, and allocation to root biomass, whereas other factors, such as the duration of immersion, salinity, and temperatures of sea water have no significant effect. According to flood resilience and growth response to sea water submergence, T. ponticum demonstrated high potential to be a dune stabilizer.


2019 ◽  
Vol 5 (2) ◽  
pp. 112
Author(s):  
Asri Mulya Setiawan ◽  
Erniati Bachtiar

This study aims to analyze the deflection capacity, ductality and stiffness of reinforced concrete beam structures reinforced by GFRP with sea water immersion for 1 year. The test method used is a monotonic loading method that uses two simple supports over the test object and is pressed at a constant ramp actuator speed of 0.05 mm / sec until the concrete beam fails. The test results show that BF0 is more ductile compared to BF6 and BF12. This can be seen the existing deflection, where BF0 has a deflection that tends to be larger than the other beams. In BF0 specimens, the load that is able to hold is greater than BN specimens, but the resulting deflection is also greater


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