scholarly journals The Fracture Toughness of PVC / GRP Sandwich Systems in Marine Environment

2008 ◽  
Vol 17 (1) ◽  
pp. 096369350801700 ◽  
Author(s):  
Cemal Koçhan ◽  
Gökdeniz Neşer ◽  
Çiçek Özes
Keyword(s):  
Fracture Toughness ◽  
Constant Temperature ◽  
Marine Environment ◽  
Environmental Conditions ◽  
Sandwich Beam ◽  
Core Material ◽  
Mode I ◽  
Foam Core ◽  
Marine Environmental

The aim of this study is to investigate experimentally the fracture toughness of sandwich systems with the PVC foam core in marine environment with a Mode-I Cracked Sandwich Beam (CSB) test arrangement. Five CSB specimens at each condition were tested. To get the values under marine environment, one set of specimen was conditioned in a 5% solution of NaCl for a 120 h period at a constant temperature of 50°C. It has been found that the fracture toughness of the PVC foam core material slightly increases under marine environmental conditions. It can be concluded that under the conditions in this study the system with the PVC core was largely unaffected by the immersion process.

scholarly journals Low temperature mixed-mode debond fracture and fatigue characterisation of foam core sandwich

2018 ◽  
Vol 22 (4) ◽  
pp. 1039-1054 ◽  
Author(s):  
Arash Farshidi ◽  
Christian Berggreen ◽  
Leif A Carlsson
Keyword(s):  
Fracture Toughness ◽  
Growth Rate ◽  
Low Temperature ◽  
Mixed Mode ◽  
Room Temperature ◽  
Sliding Mode ◽  
Fatigue Tests ◽  
Mode I ◽  
Foam Core ◽  
Climatic Chamber

This paper experimentally investigates the effects of low temperature on fracture toughness and fatigue debond growth rate in foam core sandwich composites. Mixed-mode bending specimens were statically and cyclically tested inside a climatic chamber at a low temperature (−20°C) and at room temperature (23°C) as a reference. Testing was conducted in mode I (opening) and mixed-mode I/II (opening-sliding) mode mixities. The fatigue tests results are presented according to the modified Paris–Erdogan relation. Results showed substantial fracture toughness reduction due to low temperature. Low temperature furthermore elevated the cyclic crack growth rate.

scholarly journals Failure mechanism of PMI foam core sandwich beam in bending

2015 ◽  
Vol 6 ◽  
pp. A8 ◽  
Author(s):  
Bo Wang ◽  
Yunfeng Shi ◽  
Caihua Zhou ◽  
Tong Li
Keyword(s):  
Failure Mechanism ◽  
High Speed ◽  
Sandwich Structures ◽  
Failure Process ◽  
Sandwich Beam ◽  
Maximum Principal Stress ◽  
Core Material ◽  
Foam Core ◽  
Modified Model ◽  
Damage Propagation

Polymethacrylimide (PMI) foams have been widely applied in aerospace engineering as the core material of sandwich structures. This paper proposes a modified model to predict the constitutive relation of PMI foams and compares it to existing testing data. The study is then applied to the investigation of the failure mechanism of PMI foam core sandwich beams in bending. Corresponding bending tests were carried out where a complex failure process was observed through a high-speed camera. Numerical model of the foregoing sandwich beam is developed, in which the maximum principal stress criteria is used to predict damage propagation in PMI foam core. Both results from tests and numerical simulation validate the reliability of the theoretical prediction of the failure of PMI foam core sandwich beam using the proposed modified model of PMI foams. This study provides a theoretic tool for the design of sandwich structures with PMI foam core.

scholarly journals GMED: Global Marine Environment Datasets for environment visualisation and species distribution modelling

2018 ◽  
Author(s):  
Zeenatul Basher ◽  
David A. Bowden ◽  
Mark J. Costello
Keyword(s):  
Marine Environment ◽  
Species Distribution ◽  
Environmental Conditions ◽  
Global Scale ◽  
Species Distribution Modelling ◽  
Distribution Modelling ◽  
File Formats ◽  
Distribution Ranges ◽  
Online Availability ◽  
Marine Environmental

Abstract. The Global Marine Environment Datasets (GMED) is a compilation of publicly available climatic, biological and geophysical environmental layers featuring present, past and future environmental conditions. Marine biologists increasingly utilize geo-spatial techniques with modelling algorithms to visualize and predict species biodiversity at a global scale. Marine environmental datasets available for species distribution modelling (SDM) have different spatial resolutions and are frequently provided in assorted file formats. This makes data assembly one of the most time-consuming parts of any study using multiple environmental layers for biogeography visualization or SDM applications. GMED covers the widest available range of environmental layers from a variety of sources and depths from the surface to the deepest part of the ocean. It has a uniform spatial extent, high-resolution land mask (to eliminate land areas in the marine regions), and high spatial resolution (5 arc-minute, c. 9.2 km near equator). The free public online availability of GMED enables rapid map overlay of species of interest (e.g. endangered or invasive) against different environmental conditions of the past, present and the future, and expedites mapping distribution ranges of species using popular SDM algorithms. GMED can be found at http://gmed.auckland.ac.nz/ (DOI: https://10.6084/m9.figshare.5937268).

scholarly journals Effect of Testing Method Type and Specimen Size on Mode I Fracture Toughness of Kimachi Sandstone

2019 ◽  
Vol 135 (5) ◽  
pp. 33-41 ◽  
Author(s):  
Minami KATAOKA ◽  
Yuzo OBARA ◽  
Leona VAVRO ◽  
Kamil SOUCEK ◽  
Sang-Ho CHO ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Specimen Size ◽  
Mode I ◽  
Mode I Fracture ◽  
Mode I Fracture Toughness ◽  
Testing Method

scholarly journals The effect of modified tannic acid (TA) eco-epoxy adhesives on mode I fracture toughness of bonded joints

2021 ◽  
Vol 96 ◽  
pp. 107122
Author(s):  
Mohamed Nasr Saleh ◽  
Nataša Z. Tomić ◽  
Aleksandar Marinković ◽  
Sofia Teixeira de Freitas
Keyword(s):  
Fracture Toughness ◽  
Tannic Acid ◽  
Mode I ◽  
Bonded Joints ◽  
Mode I Fracture ◽  
Mode I Fracture Toughness ◽  
Epoxy Adhesives

scholarly journals New Approaches for the Observation of Transient Phenomena in Critical Marine Environment

2021 ◽  
Vol 9 (6) ◽  
pp. 578
Author(s):  
Roberta Ferretti ◽  
Massimo Caccia ◽  
Massimo Coltorti ◽  
Roberta Ivaldi
Keyword(s):  
Mediterranean Sea ◽  
Marine Environment ◽  
Environmental Conditions ◽  
Marine Environments ◽  
Transient Phenomena ◽  
New Approaches ◽  
Marine Vehicles ◽  
New Methodologies ◽  
Biogeochemical Parameters ◽  
Very High

This paper focuses on the development of new approaches to observe transient phenomena in critical marine environments using autonomous marine vehicles (AMVs) for the acquisition of physical and biogeochemical parameters of water and seabed characterization. The connection with metrological principles, together with the adoption of observing methodologies adjustable according to the specific marine environment being studied, allows researchers to obtain results that are reliable, reproducible, and comparable with those obtained through the classic monitoring methodologies. Tests were executed in dramatically dynamic, sensitive, and fragile areas, where the study and application of new methodologies is required to observe phenomena strongly localized in space and requiring very high resolutions, in time. Moreover, the harsh environmental conditions may present risks not only for the quality and quantity of the acquired data but also for the instrumentation and the operators. This is the case, for instance, in polar marine environments in proximity of tidal glaciers and in the Mediterranean Sea in areas characterized by seabed degassing activities, where AMV-supported monitoring procedures can allow for the safe observation of not repeatable and not completely predictable events.

Sign in / Sign up

Export Citation Format

Share Document