scholarly journals A comparison of quasi-static indentation and low-velocity impact on composite overwrapped pressure vessels

2018 ◽  
Vol 52 (29) ◽  
pp. 4051-4060 ◽  
Author(s):  
Trevor Allen ◽  
Sharif Ahmed ◽  
Warren Hepples ◽  
Philippa A Reed ◽  
Ian Sinclair ◽  
...  
Keyword(s):  
Quantitative Assessment ◽  
Permanent Deformation ◽  
Pressure Vessels ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Area ◽  
Displacement Response ◽  
Static Indentation ◽  
Force Displacement

The equivalence of quasi-static indentation and low-velocity impact loading regimes has been assessed for composite overwrapped pressure vessels. Test specimens were assessed in detail in terms of the force–displacement response, and micro-focus computed tomography was used for qualitative and quantitative assessment of the associated damage to the constituent materials/interfaces. The results show that the force–displacement response follows an essentially similar pattern between the two loading regimes (within 10% for all cases). Quantitative assessment of the projected composite damage area and permanent deformation of the aluminium substrate as a function of peak indentor displacement also showed a high degree of equivalence between the loading regimes. It is concluded that quasi-static indentation represents a usable analogue for mechanistic assessment of low-velocity impact damage in the tested composite overwrapped pressure vessels.

Low-Velocity Impact Behavior of Aluminum-Fiber/Epoxy Laminates: A Comprehensive Experimental Study

2010 ◽  
Author(s):  
Mohammad Alemi-Ardakani ◽  
Akbar Afaghi-Khatibi ◽  
Abbas S. Milani ◽  
Hady Parsaiyan
Keyword(s):  
Fiber Type ◽  
Permanent Deformation ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Projectile Energy ◽  
Fiber Reinforced ◽  
Low Velocity ◽  
Velocity Impact ◽  
Central Deflection ◽  
Damage Area

Considering many potential applications of fiber reinforced metal laminates (FMLs) in sensitive structures, it is necessary to understand their mechanical behavior under impact loads. In this study, low velocity impact tests based on ASTM D7136 have been conducted on FMLs made of 1050 aluminum sheets and various types of fiber reinforced polymer (FRP) layers; namely E-Glass, Kevlar 49, and carbon T300 plain woven in the epoxy resin. Projectile energy, fiber type and the number of successive impacts are selected among important parameters that can affect the performance of FMLs. In particular, the effects of these parameters on the absorbed energy, contact force, front and rear face damage areas, central deflection and permanent deformation of FMLs have been investigated. For determining the damage area and central deflection of the specimens, an image processing method is adapted.

Fracture of laminated woven GFRP composite pressure vessels under combined low-velocity impact and internal pressure

2018 ◽  
Vol 18 (4) ◽  
pp. 1715-1728 ◽  
Author(s):  
Shokrollah Sharifi ◽  
Soheil Gohari ◽  
Masoumeh Sharifiteshnizi ◽  
Reza Alebrahim ◽  
Colin Burvill ◽  
...  
Keyword(s):  
Internal Pressure ◽  
Pressure Vessels ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Gfrp Composite ◽  
Composite Pressure Vessels

scholarly journals Ultrasonic Analysis of Damage in CFRP Resulting from Static Indentation and Low Velocity Impact

1993 ◽  
Vol 2 (3) ◽  
pp. 096369359300200
Author(s):  
H. Kaczmarek
Keyword(s):  
Impact Testing ◽  
Low Velocity Impact ◽  
Ultrasonic Tomography ◽  
Transverse Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Testing Procedures ◽  
Damage Initiation ◽  
Static Indentation ◽  
The Impact

In order to reduce hidden damage caused in CFRP by low velocity transverse impact, testing procedures must be established by understanding the impact phenomena and the roles of various parameters on damage initiation and growth. Hence, composite plates were stressed and an original method, “ultrasonic tomography,” was applied to detect delaminations on the interfaces. The results show the similarity of the damage growth resulting from static indentation and low velocity impact.

Fatigue behavior of graphene nanoplatelets reinforced and unreinforced basalt/epoxy composite pressure vessels subjected to low-velocity impact under internal pressure

2021 ◽  
pp. 002199832110370
Author(s):  
Harun Sepetcioglu ◽  
Necmettin Tarakcioglu
Keyword(s):  
Fatigue Life ◽  
Internal Pressure ◽  
Epoxy Composite ◽  
Fatigue Behavior ◽  
Pressure Vessels ◽  
Graphene Nanoplatelets ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact

In this study, the fatigue behavior of 0.25 wt.% graphene nanoplatelets (GnPs) reinforced and unreinforced impact damaged basalt/epoxy composite pressure vessels (CPVs) was investigated. The CPVs were subjected to low-velocity impact (LVI) of 2.5 J, 5 J, 7.5 J, 10 J, 15 J, 20 J, and 25 J under internal pressure of 50 bar (hoop/axial prestresses: 98/49 MPa). Then, to detect fatigue life changes, fatigue tests were performed at load rates of 30% of ultimate hoop stress (σHS), where sweat damage occurred in the basalt/epoxy CPVs under alternating internal pressure. Considering the remaining fatigue life and formation of the damages in the CPVs for all impact energies, to investigate the fatigue behavior and GnPs effects of CPVs subjected to low-velocity impact, an impact value of 5 J was preferred. The 5 J impact damaged CPVs were subjected to fatigue cyclic following ASTM D 2992 at load rates of 20%, 25%, 30%, 35%, and 40% of the σHS. The fatigue life of damaged CPVs was compared by that of undamaged over S-N curves. As the impact energy increased, the impact damage area increased. The increased size of damage reduced the fatigue life of basalt/epoxy CPVs. At the fatigue load rates mentioned above, the GnPs improved the fatigue life of damaged basalt/epoxy CPVs by about 3.5, 3.2, 11.3, 2.4, and 5 times, respectively.

Residual Strength and Failure Criterion of PP Thermoplastic Honeycomb Sandwich Subjected to Low Velocity Impact

2011 ◽  
Vol 471-472 ◽  
pp. 646-651 ◽  
Author(s):  
A. Freeda Amir ◽  
A.R. Othman
Keyword(s):  
Impact Energy ◽  
Residual Strength ◽  
Failure Modes ◽  
Structural Integrity ◽  
Peak Load ◽  
Low Velocity Impact ◽  
Honeycomb Core ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Area

This paper presented the effect of constituent materials on impact damage and strength reduction of sandwich structure, composed of laminated woven E-glass facesheets and polypropylene thermoplastic honeycomb core. Effect of low-velocity impact was the main interest in a variety of layered configurations. Compression after impact (CAI) has been carried out to determine the residual strength of impacted sandwich structures. Three different thicknesses of core of 20, 40 and 60mm subjected to three different levels of impact energy of 15, 30 and 45J were investigated. Impact response of the panel was recorded and analyzed in terms of peak load, indentation, energy absorbed and time. A profile analysis using optical 3D surfaces profiler was carried out to attain the indentation depth and damage area of the samples. The tested samples were then sectioned into halves to capture the failure mode or damaged sequence of the polypropylene thermoplastic honeycomb core. The dominant failure modes of the core indicated that polypropylene thermoplastic honeycomb core is a high strength material which can absorb higher impact energy and retain a higher degree of structural integrity.

An experimental study on quasi-static indentation, low-velocity impact and damage behaviors of laminated composites at high temperatures

2021 ◽  
pp. 096739112110169
Author(s):  
Akim Djele ◽  
Ramazan Karakuzu
Keyword(s):  
Impact Test ◽  
Laminated Composites ◽  
Low Velocity Impact ◽  
Fiber Reinforced ◽  
Transverse Loading ◽  
Low Velocity ◽  
Static Tests ◽  
Velocity Impact ◽  
Impact Tests ◽  
Static Indentation

Nowadays, fiber reinforced laminated composites are widely used in many applications due to their high strength/weight ratio. However, these materials are very sensitive to transverse loading. The low-velocity impact test has been widely used by researchers to simulate the transverse loading. However, the low-velocity impact tests are highly toilsome, and this test requires expensive hardware and software systems. To reduce the experimental costs of the low-velocity impact test, it will be more attractive, much simpler, cheaper and more widely available to achieve impact behavior using quasi-static tests. Thus, to compare both tests, in this work the absorbed energy and force-deflection curves obtained by low-velocity impact and quasi-static indentation loading in two different fiber reinforced epoxy composites have been investigated. The Carbon-Kevlar hybrid fabrics and S2 glass fabrics were used as reinforcements. For low-velocity impact tests, a range of energies was used between 20 and 80 J. For quasi-static indentation test, the crosshead speeds were increased gradually from 1 mm/min to 60 mm/min. In addition, tests at 23°C, 40°C, 60°C and 80°C were made to examine the effect of temperature on these tests. As a result of the quasi-static tests performed, the amount of energy required to perforate the samples at a certain test speed is at the same level as the low-velocity impact test. Thus, the required energy amount for the perforation of the materials can be found by performing a quasi-static test at an appropriate speed, rather than the low-velocity impact test.

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