scholarly journals Fabrication technology and shear failure behaviours of elastic–porous sandwich structure with entangled metallic wire mesh

2022 ◽  
Vol 170 ◽  
pp. 108599
Author(s):  
Xin Xue ◽  
Yuhan Wei ◽  
Fang Wu ◽  
Hongbai Bai ◽  
Chunhong Lu ◽  
...  
2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Rajinder Ghai ◽  
Prem Pal Bansal ◽  
Maneek Kumar

There is a common phenomenon of shear failure in RCC beams, especially in old buildings and bridges. Any possible strengthening of such beams is needed to be explored that could strengthen and make them fit for serviceable conditions. The present research has been made to determine the performance of predamaged beams strengthened with three-layered wire mesh polymer-modified ferrocement (PMF) with 15% styrene-butadiene-rubber latex (SBR) polymer. Forty-eight shear-designed and shear-deficient real-size beams were used in this experimental work. Ultimate shear load-carrying capacity of control beams was found at two different shear-span (a/d) ratios 1 and 3. The sets of remaining beams were loaded with different predetermined damage levels of 45%, 75%, and 95% of the ultimate load values and then strengthened with 20 mm thick PMF. The strengthened beams were then again tested for ultimate load-carrying capacity by conducting the shear load test at a/d = 1 and 3. As a result, the PMF-strengthened beams showed restoration and enhancement of ultimate shear load-carrying capacity by 5.90% to 12.03%. The ductility of strengthened beams was improved, and hence, the corresponding deflections were prolonged. On the other hand, the cracking pattern of PMF-strengthened beams was also improved remarkably.


2007 ◽  
Vol 76 (24) ◽  
Author(s):  
J. Bravo-Abad ◽  
L. Martín-Moreno ◽  
F. J. García-Vidal ◽  
E. Hendry ◽  
J. Gómez Rivas

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3176
Author(s):  
Jaeha Lee ◽  
Yoseok Jeong ◽  
Kyeongjin Kim ◽  
Ilkeun Lee ◽  
WooSeok Kim

In South Korea, the number of vehicles is gradually increasing. The number of heavy vehicles in 2010 increased up to 19% in less than five years. Therefore, the chances of heavy vehicle-concrete median barrier (CMB) collision also became higher than in the past; therefore, a need to study a stricter design level for improving the current CMB (CMB-15) under harsher environments arose. Accordingly, in the present study, a new concrete median barrier was designed under a stricter impact severity, SB6(420 kJ), compared to the current design impact severity, SB5-B (270 kJ). In particular, shock absorbing devices to absorb impact energy were applied to the CMB. An empty space allows the dowel bars to deform and absorb collision energy. Therefore, deformable CMB was designed and tested. The key parameters selected in our study were dowel bar and wire-mesh. A series of numerical analyses were conducted to evaluate the proposed new deformable CMB designs with shock absorbers. Finally, the optimal design, CMB-17S, was proposed after several evaluations of the proposed designs and a full-scale field test. It was found that, although the developed model did not accurately predict the impact sequence due to certain differences between the actual truck and the truck model, the permanent deformation after collision could be well predicted. Based on the observations from a full-scale impact test, it was recommended that the top part of the CMB should be strengthened since major volume loss occurred due to local impact, which appeared to be due to punching shear failure.


2019 ◽  
Vol 30 (15) ◽  
pp. 2241-2256 ◽  
Author(s):  
Suchao Li ◽  
Chenxi Mao

Two types of novel shape-memory alloy-based devices with three-dimensional isolation potential and deformation recovery abilities were developed. These two types of isolators, which are called shape-memory alloy pseudo-rubber isolators, were both created with martensitic shape-memory alloy wires through weaving, rolling, and punching processes, but they underwent heat treatment at different fabrication stages and for different durations. A series of mechanical tests were performed on these two types of shape-memory alloy pseudo-rubber isolators to investigate their properties under compression, shear, and combined compression–shear loading at room temperature. The restorable shear limit was then investigated, and the corresponding shear failure mechanism was discussed according to a tension test of one thin layer of the shape-memory alloy wire mesh. Subsequently, the deformation recovery ability of the shape-memory alloy pseudo-rubber isolator with residual deformation was tested through heating on a thermo-control stove. Finally, the mechanical-property stabilities, energy-dissipation abilities, and recovery abilities were compared between the two types of shape-memory alloy pseudo-rubber isolator devices. The experimental results indicated that both types of shape-memory alloy pseudo-rubber isolators had excellent residual deformation recovery abilities, and the type-I shape-memory alloy pseudo-rubber isolator device had more stable mechanical properties than the type-II shape-memory alloy pseudo-rubber isolator. The type-I shape-memory alloy pseudo-rubber isolator device is thus an ideal candidate for traditional three-dimensional isolators.


2019 ◽  
Vol 39 (5-6) ◽  
pp. 209-218
Author(s):  
Shuguang Li ◽  
Runsheng Hu ◽  
Jin Cheng ◽  
Yingcheng Hu

A lattice sandwich structure mainly consisting of jute fiber and resin epoxy was prepared. Two configurations were established, and six out-of-plane compression experiments were conducted to identify the factors affecting the mechanical properties of the samples. The specific strength of the 2D corrugated lattice truss with the struts at 30° (I1) was 3 times stronger than that of the sample with sandwich struts at 45°. The specific strength of I1 was 3.9 times stronger than that of the Kagome structure prepared using Cu–2%Be. The cost performance with respect to the specific strength of the structure I1 was 161.7 times higher than that of the Kagome structure prepared using Cu–2%Be. Three failure modes were considered, and theoretical predictions were made separately. The failure modes in the experiment were mainly shear failure and shear buckling failure in sandwich struts.


2021 ◽  
Vol 19 (2) ◽  
pp. 33-40
Author(s):  
Hari Ram Parajuli ◽  
Arjun Ghimire

5) Though a traditional material used for construction for ages, masonry is a complex composite material, and its mechanical behavior is influenced by a large number of factors, is not generally well understood. This research aims to study the methodology available in the literature to evaluate the increase in performance of masonry by applying different reinforcement options under in-plane lateral loading. Nonlinear static analysis has been carried out as part of this research to achieve the above objectives. Different unreinforced masonry wall panels were analyzed at various load conditions. Material properties for the masonry wall were taken from the experimental test results of previous literature. The walls were first checked for two failure mechanisms. The stress distributions of walls were checked in each step of analysis and shear failure, and rocking failure was found. Each wall was then analyzed for six different reinforcement options. The comparison of results obtained from the reinforced wall analysis with that of the unreinforced wall indicated significant increase in lateral load-bearing capacity and decreased wall displacement with reinforcement. The maximum increase in load-bearing capacity was achieved by adding chicken wire mesh or CFRP bands throughout the wall while the maximum decrease in displacement was achieved by adding 12 mm diameter bars at the spacing of one meter.


1986 ◽  
Vol 108 (3) ◽  
pp. 446-449 ◽  
Author(s):  
G. A. Karim ◽  
M. G. Kibrya

The combustion of a homogeneous lean methane-air stream was investigated in a vertical, cylindrical combustor of 150 mm diameter in the presence of a metallic wire mesh. Eight metallic materials were deposited in turn onto a stainless steel wire mesh by electroplating. The potential improvement in the lean blowout limit due to catalytic effects was established separately from those due to the thermal and aerodynamic contributions of the wire mesh and its holder ring. The effectiveness of the various metallic surfaces tested in the lean combustion of methane was in the following descending order: Pt → Cu → Ag → brass → Cr → Cd → Ni → stainless steel. Moreover, it was confirmed that hydrogen was more sensitive to catalytic effects extending to relatively lower temperatures than methane.


1970 ◽  
Vol 4 (1) ◽  
Author(s):  
Maya Saridewi Pascanawaty ◽  
M Sukrawa ◽  
I.A M Budiwati

Abstract: Experimental study on the strength of brick walls have been done through literature review and laboratory testing to determine flexural, compressive and shear behaviour of the walls. Four different type of walls were used consisted of walls without plastering (TP), walls with plastering (DP), walls with plastering and chicken mesh reinforcement (DPK), and walls with plastering and wire mesh M4 reinforcement (DPW). The behaviour examined included load-deformation relationship and crack pattern/mode of failure. Laboratory testing included compression test (C) namely CTP, CDP, CDPK and CDPW; bond/shear strength test (S) namely STP, SDP, SDPK, and SDPW; flexural strength tests for failure plane perpendicular to bed joints (F) namely FTP?, FDP?, FDPK?, and FDPW?; and flexural strength tests for failure plane parallel to bed joints, namely FTP//, FDP//, FDPK// and FDPW//. Prior to testing the wall, tests on constituent materials were conducted. Red brick (made in Negara) showed compressive strength of 11,03 N/mm² with water absorption of 21,84%. Compressive strength of mortar was 9,1 N/mm². For the wall specimens testing was done after 28 days. The data obtained from the wall tests showed that compression strength for CTP, CDP, CDPK and CDPW are 3,82 N/mm², 3,84 N/mm², 7,46 N/mm², and 6,33 N/mm², respectively. Values for CDP, CDPK and CDPW are 1,01; 1,95; and 1,86 greater than that for CTP. Bond strength values of STP, SDP, SDPK and SDPW are 0,11 N/mm², 0,28 N/mm², 0,54 N,mm², and 0,42 N/mm², respectively. Values for SDP, SDPK and SDPW are 2,58; 4,88; and 3,87 greater than that of STP. Flexural strength values of FTP? and FDP? are 0,93 N/mm² and 1,27 N/mm², with a failure load for FTP?, FDP?, FDPK?, and FDPW? are sebesar 8,17 KN, 25,17 KN, 31,17 KN and 40,67 KN, respectively. The values for FDP?, FDPK?, and FDPW? are 3,08; 3,82; and 4,98 greater than that of FTP?. Flexural strength values of FTP// and FDP// are 0,38 N/mm² and 0,66 N/mm², with a failure load for FTP//, FDP//, FDPK//, and FDPW// are 3,5 KN, 13,67 KN, 18,33 KN and 32,83 KN, respectively. The values for FDP//, FDPK//, and FDPW// are 3,9; 5,24; and 9,38 greater than that of FTP//. The flexural strength of FDPK and FDPW that’s not analyzed because it was a shear failure and not a flexural failure. Stiffness (EA) for CTP, CDP, CDPK, and CDPW are 725,09 KN, 1096,32 KN,  2357,64 KN, and 1869,78 KN, respectively. The last three values are 1,5; 3,3; and 2,6  greater than that for CTP. Stiffness (EI) of FTP? was 23,78 KNm2, while stiffness of FDP?, FDPK? and FDPW? are 68,68 KNm2,  96,31 KNm2 and 112,17 KNm2, respectively, or 2,9; 4,0; and 4,7 greater than that for FTP?. Stiffness (EI) of FTP// was 12,99 KNm2, while stiffness of FDP//, FDPK//, and FDPW// were 46,89 KNm2, 84,53 KNm2 and 119,51 KNm2, respectively, or 3,6; 6,5; and 9,2 greater than that for FTP//.


BioResources ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 1927-1944 ◽  
Author(s):  
Tengteng Zheng ◽  
Yanpeng Cheng ◽  
Shuai Li ◽  
Yan Zhang ◽  
Yingcheng Hu

In this study, a wood-based X-type lattice sandwich structure was fabricated by an insertion glue method using medium density fiberboard (MDF) and plywood as panels. Birch was used for the core. The mechanical properties and failure modes of the wood-based X-type lattice sandwich structure were investigated by an out-of-plane compressive test, a short beam shear test, and their matching analytical models. The out-of-plane compressive test and the compression analytical model showed that the failure mode of the plywood and birch combination was mainly shear failure in the core. The cores were broken or had sliding surfaces, while the failure mode of the MDF and birch combination was mainly shear failure of the core at both ends. Although the compression properties of the MDF and birch combination were better, the specific strength and modulus of the plywood and birch combination was larger, which align with the characteristics of lightweight and strong strength. The failure mode of the plywood and birch combination was delamination at both ends of the panel or core breakage, which indicated that this combination had better short beam shear properties. The theoretical models of the compressive /short beam shear properties were in good agreement with experimental results obtained for the plywood and birch combination.


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