scholarly journals Test and Numerical Model of Curved Steel–Concrete Composite Box Beams under Positive Moments

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2978
Author(s):  
Zhi-Min Liu ◽  
Xue-Jin Huo ◽  
Guang-Ming Wang ◽  
Wen-Yu Ji

Compared with straight steel–concrete composite beams, curved composite beams exhibit more complicated mechanical behaviors under combined bending and torsion coupling. There are much fewer experimental studies on curved composite beams than those of straight composite beams. This study aimed to investigate the combined bending and torsion behavior of curved composite beams. This paper presents static loading tests of the full elastoplastic process of three curved composite box beams with various central angles and shear connection degrees. The test results showed that the specimens exhibited notable bending and torsion coupling force characteristics under static loading. The curvature and interface shear connection degree significantly affected the force behavior of the curved composite box beams. The specimens with weak shear connection degrees showed obvious interfacial longitudinal slip and transverse slip. Constraint distortion and torsion behavior caused the strain of the inner side of the structure to be higher than the strain of the outer side. The strain of the steel beam webs was approximately linear. In addition, fine finite element models of three curved composite box beams were established. The correctness and applicability of the finite element models were verified by comparing the test results and numerical calculation results for the load–displacement curve, load–rotational angle curve, load–interface slip curve, and cross-sectional strain distribution. Finite element modeling can be used as a reliable numerical tool for the large-scale parameter analysis of the elastic–plastic mechanical behavior of curved composite box beams.

Author(s):  
Eleftherios Aggelopoulos ◽  
Graham Couchman ◽  
Mark Lawson

Composite floors are often used in building construction where beams typically span from 6 to 18 m. They are commonly used together with decking of 50 to 80 mm depth that spans 3 to 4.5 m between the beams. Rules for the minimum degree of shear connection in composite beams are presented in Eurocode 4 and other international Codes, and were derived for beams in propped construction.Eurocode 4 defines a minimum limit for the degree of shear connection, primarily to ensure that slip at the steel-concrete interface does not exceed a limiting value. This limit is proportionate to the beam span and also depends on the steel strength and the asymmetry of the flange areas of the section. Currently, many designs cannot achieve the codified degree of shear connection demands, since it is not possible to accommodate a sufficient number of shear connectors on the span as dictated by the spacing of the deck ribs. However, there are special cases which are not explicitly accounted for in Codes. This paper aims to investigate the degree of shear connection requirements in such cases, including beams that are unpropped in construction, beams that are not fully utilised in bending because serviceability criteria govern their design and beams that are predominantly loaded by point loads rather than uniform loading.The results from parametric finite element analyses carried out using ANSYS for beams in the span range of 6 to 18 m are presented. The finite element models have been calibrated against composite beam tests. Comparisons are made with the current Eurocode 4 provisions and modifications are proposed where appropriate.


2017 ◽  
Vol 893 ◽  
pp. 380-383
Author(s):  
Jun Xia ◽  
Z. Shen ◽  
Kun Liu

The tapered cross-section beams made of steel-concrete composite material are widely used in engineering constructions and their dynamic behavior is strongly influenced by the type of shear connection jointing the two different materials. The 1D high order finite element model for tapered cross-section steel-concrete composite material beam with interlayer slip was established in this paper. The Numerical results for vibration nature frequencies of the composite beams with two typical boundary conditions were compared with ANSYS using 2D plane stress element. The 1D element is more efficient and economical for the common tapered cross-section steel-concrete composite material beams in engineering.


Author(s):  
Aaron O. Akotuah ◽  
Sabah G. Ali ◽  
Jeffrey Erochko ◽  
Xia Zhang ◽  
George V. Hadjisophocleous

Connection design is critical in timber buildings since the connections tend to have lower strength than the structural members themselves and they tend to fail in a brittle manner. The effect of connection geometry on the fire performance of a hybrid steel-timber shear connection is investigated by full-scale testing. These tests were conducted by exposing the test specimens to the standard time-temperature curve defined by CAN/ULC-S101 (CAN/ULC-S101, 2007). Test results showed that the fire resistance of these connections depends on the load ratio, the type of connection and the relative exposure of the steel plate to fire. Finite element models of the connections under fire were constructed using ABAQUS/CAE and these were validated using the test results. These numerical model results correlate well with test results with ±8.32% variation.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Jing Liu ◽  
Fa-xing Ding ◽  
Xue-mei Liu ◽  
Zhi-wu Yu ◽  
Zhe Tan ◽  
...  

This study investigates the flexural strength of simply supported steel-concrete composite beams under hogging moment. A total of 24 composite beams are included in the experiments, and ABAQUS software is used to establish finite element (FE) models that can simulate the mechanical properties of composite beams. In a parametric study, the influences of several major parameters, such as shear connection degree, stud arrangement and diameter, longitudinal and transverse reinforcement ratios, loading manner, and beam length, on flexural strength were investigated. Thereafter, three standards, namely, GB 50017, Eurocode 4, and BS 5950, were used to estimate the flexural strength of the composite beams. These codes were also compared with experimental and numerical results. Results indicate that GB 50017 may provide better estimations than the other two codes.


2020 ◽  
Vol 38 (6A) ◽  
pp. 869-878
Author(s):  
Marwah S. Abduljabbar ◽  
Wael S. Baldawi ◽  
Mohammed J. Hamood

In this research, the results of three composite open web steel joist static tests are presented along with the results of companion pushout tests. The effect of shear connection degree and span-to-depth ratio on the behavior of composite open web joists under distributed static loading is reviewed and discussed, followed by a comparison of results of the shear stud strength from push-out tests, back-calculated from the ultimate capacity of the composite joist tests, and to the provisions in the AISC, EC4, NZS, SJI, and BS5950. Specimen test results of the studied span-to-depth ratios showed that the load-deflection behavior was similar to ultimate capacity difference less than 10%, but they experienced different failure modes and deflection. And when the test results were compared based on the shear connection degree, they revealed that the composite open web joist designed with partial shear connection suffered from severe deformation and deflection accompanied with higher ultimate capacity


Author(s):  
Prasannakumar S. Bhonge ◽  
Chandrashekhar K. Thorbole ◽  
Hamid M. Lankarani

The aircraft seat dynamic performance standards as per CFR 14 FAR Part 23, and 25 requires the seat to demonstrate crashworthy performance as evaluated using two tests namely Test-I and Test-II conditions. Test-I dynamic test includes a combined vertical and longitudinal dynamic load to demonstrate the compliance of lumbar load requirement for a Hybrid II or an FAA Hybrid III Anthropomorphic Test Device (ATD). The purpose of this test is to evaluate the means by which the lumbar spine of the occupant in an impact landing can be reduced. This test requirement is mandatory with every change in the seat design or the cushion geometry. Experimental full-scale crash testing is expensive and time-consuming event when required to demonstrate the compliance issue. A validated computational technique in contrast provides an opportunity for the cost effective and fast certification process. This study mainly focuses on the characteristics of DAX foams, typically used as aircraft seat cushions, as obtained both at quasi-static loading rate and at high loading rate. Nonlinear finite element models of the DAX foam are developed based on the experimental test data from laboratory test results conducted at different loading rates. These cushion models are validated against sled test results to demonstrate the validity of the finite element models. The results are compared for these computational sled test simulations with each seat cushion as obtained using quasi-static and high-loading rate characteristics. The result demonstrates a better correlation of the simulation data with the full scale crash test data for the DAX foam when high loading rate data is utilized instead of quasi-static data in the dynamic finite element models. These models can be utilized in the initial design of the aircraft seats, and thus reducing the cost and time of a full-scale sled test program.


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