scholarly journals Flexural Performance Evaluation of Novel Wide Long-Span Composite Beams Used to Construct Lower Parking Structures

2019 ◽  
Vol 12 (1) ◽  
pp. 98
Author(s):  
Yun-Chul Choi ◽  
Doo-Sung Choi ◽  
Keum-Sung Park ◽  
Kang-Seok Lee

Efficient parking structures are urgently required in Korea. The design of parking structures more than 8 m in height is difficult because both fire and seismic resistance must be considered. Existing designs are uneconomical and conservative. However, the design of parking structures less than 8 m in height is relatively simple and there are few restrictions to the construction. It is essential to optimize the design of parking structures less than 8 m in height. Here, we describe novel wide long-span composite beams that reduce the story height of low parking structures. The flexural capacity of seven of the beams was evaluated; all beams were loaded at two points prior to monotonic bending tests. We also performed finite element analysis (FEA) based on the material properties of the test specimens, and compared the results to those of the structural tests. The flexural strength of the wide composite steel beams increased by approximately 20% as the steel thickness rose by 3 mm, from 6 to 9 mm. The rebar shape (triangular or rectangular) did not affect flexural strength. The flexural strength of beams without rebar was 10% less than that of beams with rebar. The FEA and test results were in good agreement. The section plastic moments were free from global and local instability.

2020 ◽  
Vol 30 (4) ◽  
pp. 21-32
Author(s):  
Palanivelu Sangeetha ◽  
S. Ramana Gopal ◽  
A. Jai Vigneshwar ◽  
K. Vaishnavi ◽  
A. Srinidhi

Abstract This study investigates the flexural strength of simply-supported steel–concrete composite beams under two-point loading. A total of four specimens were tested to failure for varying parameters including type of connectors (stud and channel) and number of connectors (two and four). ANSYS software was used to establish the finite element models that can simulate the flexural behaviour of the composite beam. The test results show that a beam with channel connectors performs better than a beam with stud connectors. The composite beam with two connectors between the beam and slab causes additional deflection due to slippage in the connectors, when compared to the beam with four connectors. The results from the analytical model are in good agreement with the experimental results.


2021 ◽  
pp. 136943322110073
Author(s):  
Erdem Selver ◽  
Gaye Kaya ◽  
Hussein Dalfi

This study aims to enhance the compressive properties of sandwich composites containing extruded polystyrene (XPS) foam core and glass or carbon face materials by using carbon/vinyl ester and glass/vinyl ester composite Z-pins. The composite pins were inserted into foam cores at two different densities (15 and 30 mm). Compression test results showed that compressive strength, modulus and loads of the sandwich composites significantly increased after using composite Z-pins. Sandwich composites with 15 mm pin densities exhibited higher compressive properties than that of 30 mm pin densities. The pin type played a critical role whilst carbon pin reinforced sandwich composites had higher compressive properties compared to glass pin reinforced sandwich composites. Finite element analysis (FE) using Abaqus software has been established in this study to verify the experimental results. Experimental and numerical results based on the capabilities of the sandwich composites to capture the mechanical behaviour and the damage failure modes were conducted and showed a good agreement between them.


2017 ◽  
Vol 09 (08) ◽  
pp. 1750117 ◽  
Author(s):  
Dongpeng Ma ◽  
Yiping Liu ◽  
Nanli Zhang ◽  
Zhenyu Jiang ◽  
Liqun Tang ◽  
...  

Epoxy polymer concrete (EPC) has been widely used in civil engineering nowadays due to its excellent mechanical properties and advantages in processing. In this paper, a modeling study has been carried out on the flexural performance of EPC. Two classic micromechanics models, i.e. rule of mixture and Mori-Tanaka method, are introduced to predict the flexural strength of EPC with various epoxy resin contents. The comparison shows that the parallel model based on the rule of mixture attains a good agreement with the measured results when the epoxy resin content is sufficiently high to achieve strong adhesion between the aggregate and the epoxy resin. In contrast, the Mori–Tanaka method with the failure criterion dominated by the weakest phase fails to give acceptable prediction due to the unsuitability of its basic assumptions to EPC, particularly when the epoxy resin content is at relatively high levels.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Liufeng Zhang ◽  
Yinghua Yang

In view of the characteristics of a high floor and the heavy load of logistics buildings, a partially prefabricated partially encased assembled composite beam (PPEC) is proposed in order to achieve the low cost construction of such buildings. In this research, the mechanical properties of PPEC beams were studied experimentally. The effects of the concrete strength grade, steel content, shear span ratio, and fabrication methods on the mechanical properties of the PPEC beams were analyzed. The results showed that the proposed structural form of the PPEC beams was generally feasible. Based on the test results, a practical shear formula for PPEC beams was proposed, and the calculated results were in good agreement with the test results.


2014 ◽  
Vol 590 ◽  
pp. 312-315
Author(s):  
Wei Hong Xuan ◽  
Pan Xiu Wang ◽  
Yu Zhi Chen ◽  
Xiao Hong Chen

The dry shrinkage deformation of polypropylene fiber mortar was analyzed by ANSYS software and compared with experiment value in this paper. The error of the calculated and experimental results in the 14 days and 28 days are 7.8% and 10.5%. It can be found that the calculated results are in good agreement with test results. The results indicate that the dry shrinkage value of polypropylene fiber mortar is lower than ordinary mortar. Adding polypropylene fibers can inhibit the process of cracking and improve the fracture toughness of cement-based materials.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Jikai Zhou ◽  
Pingping Qian ◽  
Xudong Chen

The size dependence of flexural properties of cement mortar and concrete beams is investigated. Bazant’s size effect law and modified size effect law by Kim and Eo give a very good fit to the flexural strength of both cement mortar and concrete. As observed in the test results, a strong size effect in flexural strength is found in cement mortar than in concrete. A modification has been suggested to Li’s equation for describing the stress-strain curve of cement mortar and concrete by incorporating two different correction factors, the factors contained in the modified equation being established empirically as a function of specimen size. A comparison of the predictions of this equation with test data generated in this study shows good agreement.


2013 ◽  
Vol 834-836 ◽  
pp. 720-725 ◽  
Author(s):  
Hai Liang Wang ◽  
Wei Chang ◽  
Xin Lei Yang

Six reinforced concrete beams, including 4 beams strengthened with BFRP sheets at different layer of BFRP sheets and 2 control beams, are tested to investigate the effect of layer of BFRP sheets on the ultimate flexural resistance and load-deflection response of the pre-damaged concrete beams strengthened with BFRP sheets. Results show that the flexural resistance of pre-damaged concrete beams increases along with the BFRP sheets layer increasing,but the flexural resistance enhances the degree not to assume the linear relations to the enforcement layer.Numerical simulation of the pre-damaged concrete beams strengthened with BFRP sheets is conducted by ANSYS, and the results of numerical simulation are compared with those of the test results. It turns out that the results of numerical simulation are in good agreement with the test results.


Author(s):  
Yang-Fei Zhang ◽  
Min Miao ◽  
Yu-Feng Jin ◽  
Shu-Lin Bai

The effect of embedded channels and cavities on the strength of LTCC substrates has been investigated by experiments, theoretical analysis and finite element analysis (FEA) simulation. The fracture behaviors characterized by flexural strength were measured by three-point bending tests and discussed according to the features of the microstructure, which was studied by Scanning Electron Microscope, Energy Spectrum Analysis and X-Ray Diffraction methods. The experimental results show that X and Y-axial channels have little effect on the flexural strength while Z-axial via-hole will greatly lower the strength due to the stress concentration. Two distinct components were observed: particles composed of synthetic corundum and matrix composed of corundum, silica, aluminum, and sodium calcium aluminum silicate. The FEA simulation gave similar results to the experiments and theoretical calculations and proved to be an effective method to predict possible condition of the fracture on substrates with complex internal structures.


2020 ◽  
Vol 984 ◽  
pp. 230-238
Author(s):  
Yun Yan Liu ◽  
Ying Fang Fan

In order to explore the flexural behavior of CFRP reinforced pre-stressed concrete (PC) beams with initial cracks, 6 pre-tensioned beams were manufactured. Then the beams were pre-loaded to crack with 40% and 60% ultimate load respectively, and the beams were strengthened by CFRP under the conditions of load holding and fully unloaded. After that, the four-points bending tests were performed, and beam section strains, flexural capacities and cracks were analyzed. The results demonstrate that the ultimate load of CFRP reinforced beams increased by 10%~18%, and the ultimate loads of CFRP reinforced load holding beams were 3% and 6% lower than that of CFRP reinforced non-destructive beam, and the inhibiting effect of CFRP on cracks was weakened, the hysteresis strains should be considered for them. In this paper, the fiber hysteresis strains were calculated by the method of full section decompression moment, and the flexural capacities of CFRP reinforced PC beams were calculated, which are in good agreement with the test results.


2019 ◽  
Vol 30 (17) ◽  
pp. 2581-2594 ◽  
Author(s):  
J David Brigido-González ◽  
Steve G Burrow ◽  
Benjamin KS Woods

One of the persistent challenges facing the development of morphing aerostructures is the need to have material and structural solutions which provide a compromise between the competing design drivers of low actuation energy and high stiffness under external loads. This work proposes a solution to this challenge in the form of a novel switchable stiffness structural concept based on the principle of granular jamming. In this article, the concept of using granular jamming for controlling stiffness is first introduced. Four-point bending tests are used to obtain the flexural rigidity and bending stiffness of three different granular materials under different levels of applied vacuum loading. Nonlinear finite element analysis simulations using experimentally derived nonlinear material properties show good agreement with experiment. A specific application of this concept is then proposed based on the Fish Bone Active Camber morphing airfoil. A unit cell of this concept is built, tested and analysed, followed by the first prototype of a complete switchable stiffness Fish Bone Active Camber morphing airfoil, which is experimentally shown to be able to achieve an increase in stiffness of up to 300% due to granular jamming.


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