scholarly journals Impact and Post-Impact Performance of Sandwich Wall Boards with GFRP Face Sheets and a Web-Foam Core: The Effects of Impact Location

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1714 ◽  
Author(s):  
Yiwei Xia ◽  
Xiaoping Li ◽  
Yu Peng ◽  
Mianheng Lai ◽  
Lu Wang
Keyword(s):  
Mechanical Performance ◽  
Loading Capacity ◽  
Foam Core ◽  
Impact Performance ◽  
Impact Location ◽  
Post Impact ◽  
Sandwich Wall ◽  
Ultimate Loading Capacity ◽  
The Impact ◽  
Ultimate Loading

In recent years, load-bearing exterior sandwich wall boards have been adopted in civil engineering. The exterior walls of structures are often exposed to low velocity impacts such as stones, tools, and windborne debris, etc. The ultimate loading capacity, deformation, and ductility of sandwich walls are weakened by impact loads. In this study, the sandwich wall boards consisted of glass fiber reinforced plastic (GFRP) face sheets and a web-foam core. The core of wall boards was not the isotropic material. There was no doubt that the mechanical performance was seriously influenced by the impact locations. Therefore, it is necessary to carry out an investigation on the impact and post-impact performance of exterior wall boards. A comprehensive testing program was conducted to evaluate the effects of impact locations and impact energies on the maximum contact load, deflection, and contact time. Meanwhile, the compression after impact (CAI) performance of wall boards were also studied. The results indicated that the impact location significantly affects the performance of wall boards. Compared with an un-damaged wall board, the residual ultimate loading capacity of damaged wall boards reduced seriously, which were not larger than 50% of the designed ultimate loading capacity.

scholarly journals Impact Performance and Bending Behavior of Carbon-Fiber Foam-Core Sandwich Composite Structures in Cold Arctic Temperature

2020 ◽  
Vol 4 (3) ◽  
pp. 133
Author(s):  
M.H. Khan ◽  
Bing Li ◽  
K.T. Tan
Keyword(s):  
Carbon Fiber ◽  
Impact Damage ◽  
Matrix Cracking ◽  
Face Sheet ◽  
Foam Core ◽  
Impact Performance ◽  
Post Impact ◽  
Bending Behavior ◽  
Impact Bending ◽  
The Impact

This study investigates the impact performance, post-impact bending behavior and damage mechanisms of Divinycell H-100 foam core with woven carbon fiber reinforced polymer (CFRP) face sheets sandwich panel in cold temperature Arctic conditions. Low-velocity impact tests were performed at 23, −30 and −70 °C. Results indicate that exposure to low temperature reduces impact damage tolerance significantly. X-ray microcomputed tomography is utilized to reveal damage modes such as matrix cracking, delamination and fiber breakage on the CFRP face sheet, as well as core crushing, core shearing and debonding in the Polyvinyl Chloride (PVC) foam core. Post-impact bending tests reveal that residual flexural properties are more sensitive to the in-plane compressive property of the CFRP face sheet than the tensile property. Specifically, the degradation of flexural strength strongly depends on pre-existing impact damage and temperature conditions. Statistical analyses based on this study are employed to show that flexural performance is dominantly governed by face sheet thickness and pre-bending impact energy.

Fibre-Cement Paste Transition Zone

1994 ◽  
Vol 370 ◽  
Author(s):  
Vahan Agopyan ◽  
Holmer Savastano
Keyword(s):  
Transition Zone ◽  
Mechanical Performance ◽  
Mechanical Tests ◽  
Polypropylene Fibres ◽  
Impact Performance ◽  
The Matrix ◽  
Vegetable Fibre ◽  
Electron Image ◽  
Backscattered Electron ◽  
The Impact

AbstractThe characteristics of fibres and paste of ordinary Portland cement transition zone are analysed and correlated to the mechanical properties of the produced composites. The water-cement ratio of the matrix varies from 0.30 to 0.46 and the age of the specimens varies from 7 to 180 days. Composites of vegetable fibres (coir, sisal and malva) are compared with those of chrysotile asbestos and polypropylene fibres. The analysis is made by backscattered electron image (BSEI) and energy dispersive spectroscopy (EDS). Mechanical tests evaluate the composite tensile strength and ductility.Mainly for vegetable fibre composites the transition zone is porous, cracked and rich in calcium hydroxide macrocrystals. These results are directly associated with the fibre-matrix bonding and with the composite mechanical performance. Further studies considering the impact performance of the composites compare the porosity of the transition zone with the toughness of the composites.

Linking the Impact Force History with Residual Mechanical Characteristics and NDI - A Smart Way to Perform SHM in Composites

2008 ◽  
Vol 56 ◽  
pp. 524-529 ◽  
Author(s):  
Nicolae Constantin ◽  
Viorel Anghel ◽  
Mircea Găvan ◽  
Ştefan Sorohan
Keyword(s):  
Composite Materials ◽  
Mechanical Characteristics ◽  
Structural Integrity ◽  
Mechanical Performance ◽  
Impact Force ◽  
Layered Composite ◽  
Damage Level ◽  
Clear Link ◽  
Post Impact ◽  
The Impact

Structural integrity monitoring (SHM) and evaluation of residual mechanical performance are highly needed in assessing the post-impact behaviour of composite materials and structures. The link between impact force history and the damage level was not followed enough in research studies upon the SHM of composites. The authors put in evidence a clear link in this matter in a variety of layered composite materials. The link was assessed by evaluating the residual mechanical performance and by nondestructive inspection (NDI) – ultrasonics and infrared thermography (IRT) - on the impacted samples. Such a link may prove a very useful and reliable shortcut for backing the online SHM and condition based maintenance.

scholarly journals Biopolymer-Waste Fiber Reinforcement for Earthen Materials: Capillary, Mechanical, Impact, and Abrasion Performance

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1819
Author(s):  
Héctor Gonzalez-Calderon ◽  
Gerardo Araya-Letelier ◽  
Sabine Kunze ◽  
Claudia Burbano-Garcia ◽  
Úrsula Reidel ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Fiber Reinforcement ◽  
Impact Performance ◽  
Mechanical Impact ◽  
Chicken Feathers ◽  
Earthen Construction ◽  
The Impact ◽  
Positive Effect ◽  
By Products ◽  
Significant Increment

The poultry industry, highly prevalent worldwide, generates approximately 7.7 × 106 metric tons of chicken feathers (CFs), which become a major environmental challenge due to their disposal when considered waste or due to their energy transformation consumption when considered by-products. CFs are mainly composed of keratin (approximately 90%), which is one of the most important biopolymers whose inherent characteristics make CFs suitable as biopolymer fibers (BPFs). This paper first assesses the morphological and chemical characteristics of these BPFs, through scanning electron microscopy and energy dispersive X-ray spectroscopy, and then evaluates the waste valorization of these BPFs as a sustainable alternative for fiber-reinforcement of earthen mixes intended for earthen construction, such as adobe masonry, rammed earth, and earthen plasters. In particular, four earthen mixes with increasing doses of BPFs (i.e., 0%, 0.25%, 0.5%, and 1% of BPFs by weight of soil) were developed to evaluate the impact of BPF-reinforcement on the capillary, mechanical, impact, and abrasion performance of these earthen mixes. The addition of BPFs did not significantly affect the mechanical performance of earthen mixes, and their incorporation had a statistically significant positive effect on the impact performance and abrasion resistance of earthen mixes as the BPF dose increased. On the other hand, the addition of BPFs increased the capillary water absorption rate, possibly due to a detected increment in porosity, which might reduce the durability of water-exposed BPF-reinforced earthen mixes, but a statistically significant increment only occurred when the highest BPF dose was used (1%).

scholarly journals Thermoplastic RTM: Impact Properties of Anionically Polymerised Polyamide 6 Composites for Structural Automotive Parts

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5790
Author(s):  
James J. Murray ◽  
Tom Allen ◽  
Simon Bickerton ◽  
Ankur Bajpai ◽  
Klaus Gleich ◽  
...  
Keyword(s):  
Glass Fibre ◽  
High Speed ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Polyamide 6 ◽  
Automotive Applications ◽  
Impact Performance ◽  
Out Of Plane ◽  
Post Impact ◽  
The Impact

This study investigates the impact behaviour and post-impact performance of polyamide-6 glass fibre reinforced composites, manufactured by thermoplastic resin transfer moulding. Impact test samples were extracted from quasi-isotropic laminates using two different glass fibre sizings, both with a fibre volume fraction of approximately 52%. A previous study showed that one of these sizings enhanced the interfacial strength and Mode I fracture toughness; however, the effects of the sizing on out-of-plane impact is of greater significance in terms of automotive applications. A drop-weight impact tester was used to determine out-of-plane impact performance for both sizings in terms of impact load-induced and energy returned from the striker. High-speed video of the impact response was simultaneously captured. Testing was carried out at three impact energy levels: two sub-penetration and one full penetration. The impact damage area was observed, and the post-damage compression properties of samples were measured to determine the reduction in their strength and stiffness. Results showed that the use of different sizing technologies had little effect on the post-impact compressive properties and that penetration led to only a 29% drop in compression strength. Overall, the outcomes of this work demonstrate the potential of these materials in automotive applications.

Sign in / Sign up

Export Citation Format

Share Document