156
X. Bi et al.
Material Exploitation at Safe Design of Composite Airframe Structures by Accurate
Simulation of Collapse) and POSICOSS (Improved Post-buckling Simulation for
Design of Fiber Composite stiffened Fuselage Structures) [2] etc.
The bearing capacity of composite stiffened panel is easily affected by low velocity
impact damage that may occur during the working process of tool dropping, runway
gravel and hail [3, 4]. In the impact damage, both barely visible impact damage
(BVID) and visible impact damage (VID) can be encountered and cause a significant decrease in structural strength and endanger flight safety. In addition, reinforced
composite materials often bear in-plane compression load and shear load during
aircraft service, so relevant researchers have carried out a lot of research work on
composite stiffened panels after impact [5–22]. Buckling and post buckling behavior
of Glare laminates containing splices and doublers were researched from both instrumented tests [5] and numerical modelling [6]. Yu Feng et al. investigated effect
of impact damage positions on the buckling and post-buckling behaviors of stiffened composite panel under compression load [7], shear load [8], fatigue load and
compression-after-impact- fatigue (SAIF) load [9] and shear-after-impact- fatigue
(SAIF) behaviors [10]. Sun Wei et al. [11, 12] made an experimental and finite
element research on effect of stiffener damage caused by low velocity impact on
compressive buckling and failure modes of T-stiffened composite panels. In addition,
the edge impact damage, which shows different damage mechanism on CompressionAfter-Impact (CAI) behavior of stiffened composite panels, is discussed in [13]. The
panel style is also a research point, except T-stiffened panel [14–16], J-stiffened
panel [17–19] and hat-stiffened panel [20–22]. It is found that the research on the
bearing capacity of stiffened panels after impact is mainly focused on compression
load, while the research on in-plane shear load is limited, especially for the research
on the influence of delamination position and size on the post buckling performance
of structures, there is still a lack of targeted research work. Therefore, this paper will
focus on the failure mechanism of composite stiffened panels under in-plane shear
loading.
13.2 Question Description
13.2.1 Configuration and Size of Specimen
In this project, the effect of embedded damage on load-bearing failure and post
buckling performance of three stringer stiffened panels under shear load is studied.
Two kinds of simulation models are studied: nondestructive model and embedded
delamination damage model. The type of stringer is type I. The configuration and
detailed dimensions of the test piece are shown in Fig. 13.1. The configuration size
and section of type I stringer are shown in Fig. 13.2. The paving of each part of the
stiffened plate is shown in Table 13.1. Among them, the skin and the stringer are
glued together, and the adhesive film is J-116b with a thickness of 0.2 mm.
X. Bi et al.
Material Exploitation at Safe Design of Composite Airframe Structures by Accurate
Simulation of Collapse) and POSICOSS (Improved Post-buckling Simulation for
Design of Fiber Composite stiffened Fuselage Structures) [2] etc.
The bearing capacity of composite stiffened panel is easily affected by low velocity
impact damage that may occur during the working process of tool dropping, runway
gravel and hail [3, 4]. In the impact damage, both barely visible impact damage
(BVID) and visible impact damage (VID) can be encountered and cause a significant decrease in structural strength and endanger flight safety. In addition, reinforced
composite materials often bear in-plane compression load and shear load during
aircraft service, so relevant researchers have carried out a lot of research work on
composite stiffened panels after impact [5–22]. Buckling and post buckling behavior
of Glare laminates containing splices and doublers were researched from both instrumented tests [5] and numerical modelling [6]. Yu Feng et al. investigated effect
of impact damage positions on the buckling and post-buckling behaviors of stiffened composite panel under compression load [7], shear load [8], fatigue load and
compression-after-impact- fatigue (SAIF) load [9] and shear-after-impact- fatigue
(SAIF) behaviors [10]. Sun Wei et al. [11, 12] made an experimental and finite
element research on effect of stiffener damage caused by low velocity impact on
compressive buckling and failure modes of T-stiffened composite panels. In addition,
the edge impact damage, which shows different damage mechanism on CompressionAfter-Impact (CAI) behavior of stiffened composite panels, is discussed in [13]. The
panel style is also a research point, except T-stiffened panel [14–16], J-stiffened
panel [17–19] and hat-stiffened panel [20–22]. It is found that the research on the
bearing capacity of stiffened panels after impact is mainly focused on compression
load, while the research on in-plane shear load is limited, especially for the research
on the influence of delamination position and size on the post buckling performance
of structures, there is still a lack of targeted research work. Therefore, this paper will
focus on the failure mechanism of composite stiffened panels under in-plane shear
loading.
13.2 Question Description
13.2.1 Configuration and Size of Specimen
In this project, the effect of embedded damage on load-bearing failure and post
buckling performance of three stringer stiffened panels under shear load is studied.
Two kinds of simulation models are studied: nondestructive model and embedded
delamination damage model. The type of stringer is type I. The configuration and
detailed dimensions of the test piece are shown in Fig. 13.1. The configuration size
and section of type I stringer are shown in Fig. 13.2. The paving of each part of the
stiffened plate is shown in Table 13.1. Among them, the skin and the stringer are
glued together, and the adhesive film is J-116b with a thickness of 0.2 mm.