abstract A beam structure composed of CFRP box with infill concrete is studied for an application under transverse
and axial loads. This paper highlights the shear deformation of box beams under empty condition and
concrete-filled condition by simulating the beams tested in an experiment with finite element method.
Firstly, empty CFRP box beam is studied. Shear deformation contributes with about 60% of total beam
deflection. Furthermore, different analyses with perfect bond assumption and slip assumption are per-
formed to investigate concrete–CFRP interface interaction in a filled beam. From these analyses, slip
between concrete and CFRP is evident in the experiment. Consequently, the shear deformation of CFRP
becomes very high and the stiffness of the beam is not improved even with concrete infill. Effect of axial
load on friction mobilization and P-delta effect are also discussed in relation to the deformation behav-
iour of concrete-filled beams.9831
2008 Elsevier Ltd. All rights reserved.provided that composite action between concrete and tube was
fully developed. Analytical investigation of the interface interaction
between concrete and FRP is, therefore, necessary for a concrete–
FRP box beam. Also, a very large P-delta effect was observed with
secondary moment being as high as 45% of primary moment. Car-
bon fibre was proposed as a replacement of glass fibre to minimize
the effect. Thus, the P-delta effect needs to be investigated for a
CFRP box/tube beam structure. Additionally, shear behaviour of
an FRP box beam remained yet to be described.
Very high specific strength and specific stiffness of CFRP can be
utilized in structures with CFRP as a primary structural element. A
beam structure composed of CFRP box filled with concrete has
been considered to act under transverse and axial loads for a large
scale structural application as a modular unit [12]. The anisotropic
nature of CFRP and the interface between concrete and CFRP neces-
sitate an extensive study of the beam structure before realizing it
for a practical application [13]. The present research starts from
the study of one empty CFRP box beam to investigate the CFRP-
only response and finally explains the response of four concrete-
filled CFRP box beams. In this paper, shear and interface behaviours
of CFRP box beams working under four-point-bending load along
with axial compressive load are highlighted based on the results
of a finite element analysis and on their comparison with results
from an experiment.
2. Experimental programme and beam details
This work is part of a collaborated study project to investigate
the response of concrete-filled CFRP box beams subjected under
transverse and axial loads. An experimental study has been per-
formed by joint researchers. This paper considers the test of an
empty beam (E) and four concrete-filled beams (F). One empty
beam and one filled beam were tested under four point-bending
load. Remaining three concrete-filled beams were subjected to ax-
ial load in addition to transverse load. Depending upon the ratio of
mid-span bending moment to axial load, which was maintained
constant during the entire range of loading for a beam, filled beams
are classified as F-1, F-32, F-16 and F-04 with the ratio as 1, 0.32,
0.16 and 0.04, respectively. The geometry of the beams is shown in
Fig. 1. CFRP box is composed of 5 mm thick cross-ply CFRP lami-
nate. The effective span of the beams is 850 mm except for the F-
1beamwhich has an effective span of 900 mm. Experimental con-
sequences are explained in this paper in association with the re-
sults from the finite element analysis performed for the five
beams as tested in the experiment. 复合材料结构英文文献和中文翻译:http://www.751com.cn/fanyi/lunwen_8670.html