Load-bearing capacity of wood polyvinyl chloride composite log-walls with openings strengthened with steel flat bars via experimental and numerical studies

Structures ◽  
2022 ◽  
Vol 37 ◽  
pp. 242-254
Author(s):  
Warawit Eakintumas ◽  
Tawich Pulngern ◽  
Vichai Rosarpitak ◽  
Narongrit Sombatsompop
2018 ◽  
Vol 196 ◽  
pp. 01008 ◽  
Author(s):  
Vadim Alpatov ◽  
Alexey Soloviev

There is a tendency to reduce weight of load-bearing metal structures being developed and successfully realized in modern building construction. This idea serves as a basis for a whole scientific direction, named Development and application of light steel thin-walled structures (LSTS). Among them, LTST built with pop-rivets and thread-cutting screws are most widespread due to their simplicity and relative cheapness This paper presents numerical studies of LSTS joint assembly units built with screws and their load bearing capacity. The peculiarity of these units consists in misalignment of joint elements. The calculation was performed in the SolidWorks Simulation System. The modeled node is a three-dimensional assembly consisting of solid components. The results of the study are as follows: 1) thin-walled profiles have a significant sensitivity to eccentricity; 2) it is unacceptable to disregard eccentricities for thin-walled profiles and their joint connections; 3) eccentricities should be compensated by measures to improve reliability in joint connections design.


2018 ◽  
Vol 247 ◽  
pp. 00009
Author(s):  
Kamil Kmiecik ◽  
Tomasz Domański

Members of building structures are often made of wood. There are many advantages of using timber, such as quick erection time, good environmental influence and high energy efficiency. But the fire safety requirement is one of the most important issues concerning the design of timber structures. Safe use in structures depends on a proper knowledge and modelling of the chemical and physical reactions related to the increase of temperature inside the timber members. This paper presents a summary of results from numerical studies on the heat transfer through timber members exposed to fire from different sides. The finite element software SAFIR was used to make two-dimensional thermal models of the timber elements. Then the FE models were used to analyze the heat flow within the members under standard ISO-fire exposure interacting from different sides. On the basis of the 300 °C isotherms, residual cross-sections were determined. Then, the load-bearing capacity of the elements exposed to fire from different sides was determined. The obtained results showed that the location of construction members against the fire has a significant impact of the temperature distribution in the cross-section and, as a result, on the load-bearing capacity of the timber members.


2020 ◽  
Vol 62 (1) ◽  
pp. 55-60
Author(s):  
Per Heyser ◽  
Vadim Sartisson ◽  
Gerson Meschut ◽  
Marcel Droß ◽  
Klaus Dröder

2017 ◽  
Vol 68 (1) ◽  
pp. 94-100
Author(s):  
Oana Tanculescu ◽  
Adrian Doloca ◽  
Raluca Maria Vieriu ◽  
Florentina Mocanu ◽  
Gabriela Ifteni ◽  
...  

The load-bearing capacity and fracture pattern of direct inlay-retained FRC FDPs with two different cross-sectional designs of the ponticwere tested. The aim of the study was to evaluate a new fibre disposition. Two types of composites, Filtek Bulk Fill Posterior Restorative and Filtek Z250 (3M/ESPE, St. Paul, MN, USA), and one braided polyethylene fibre, Construct (Kerr, USA) were used. The results of the study suggested that the new tested disposition of the fibres prevented in some extend the delamination of the composite on buccal and facial sides of the pontic and increased the load-bearing capacity of the bridges.


2021 ◽  
Vol 60 (1) ◽  
pp. 503-518
Author(s):  
Juan Han ◽  
Lu Zhu ◽  
Hai Fang ◽  
Jian Wang ◽  
Peng Wu

Abstract This article proposed an innovative composite sandwich structure reinforced with trapezoidal latticed webs with angles of 45°, 60° and 75°. Four specimens were conducted according to quasi-static compression methods to investigate the compressive behavior of the novel composite structures. The experimental results indicated that the specimen with 45° trapezoidal latticed webs showed the most excellent energy absorption ability, which was about 2.5 times of the structures with vertical latticed webs. Compared to the traditional composite sandwich structure, the elastic displacement and ultimate load-bearing capacity of the specimen with 45° trapezoidal latticed webs were increased by 624.1 and 439.8%, respectively. Numerical analysis of the composite sandwich structures was carried out by using a nonlinear explicit finite element (FE) software ANSYS/LS-DYNA. The influence of the thickness of face sheets, lattice webs and foam density on the elastic ultimate load-bearing capacity, the elastic displacement and initial stiffness was analyzed. This innovative composite bumper device for bridge pier protection against ship collision was simulated to verify its performance. The results showed that the peak impact force of the composite anti-collision device with 45° trapezoidal latticed webs would be reduced by 17.3%, and the time duration will be prolonged by about 31.1%.


Friction ◽  
2021 ◽  
Author(s):  
Luyao Gao ◽  
Xiaoduo Zhao ◽  
Shuanhong Ma ◽  
Zhengfeng Ma ◽  
Meirong Cai ◽  
...  

AbstractSilicone elastomers-based materials have been extensively involved in the field of biomedical devices, while their use is extremely restricted due to the poor surface lubricity and inherent hydrophobicity. This paper describes a novel strategy for generating a robust layered soft matter lubrication coating on the surface of the polydimethylsiloxane (PDMS) silicone elastomer, by entangling thick polyzwitterionic polyelectrolyte brush of poly (sulfobetaine methacrylate) (PSBMA) into the sub-surface of the initiator-embedded stiff hydrogel coating layer of P(AAm-co-AA-co-HEMA-Br)/Fe, to achieve a unified low friction and high load-bearing properties. Meanwhile, the stiff hydrogel layer with controllable thickness is covalently anchored on the surface of PDMS by adding iron powder to provide catalytic sites through surface catalytically initiated radical polymerization (SCIRP) method and provides high load-bearing capacity, while the topmost brush/hydrogel composite layer is highly effective for aqueous lubrication. Their synergy effects are capable of attaining low friction coefficient (COFs) under wide range of loaded condition in water environment with steel ball as sliding pair. Furthermore, the influence of mechanical modulus of the stiff hydrogel layer on the lubrication performance of layered coating is investigated, for which the COF is the lowest only when the modulus of the stiff hydrogel layer well matches the PDMS substrate. Surprisingly, the COF of the modified PDMS could remain low friction (COF < 0.05) stably after encountering 50,000 sliding cycles under 10 N load. Finally, the surface wear characterizations prove the robustness of the layered lubricating coating. This work provides a new route for engineering lubricious silicon elastomer with low friction, high load-bearing capacity, and considerable durability.


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