On energy‐absorbing mechanisms of metal/WF‐CFRP hybrid composite columns

Abstract

Hybrid material system, comprised of metal and carbon fiber reinforced plastic (CFRP), combines the excellent mechanical performance and lightweight feature of CFRP with the competitive material cost and superior toughness of metal. By virtue of such mingled feature, metal/CFRP hybrid structure exhibits great potential in automotive components. This study aims to investigate the crushing behavior of aluminum/WF‐CFRP (woven fabric CFRP) hybrid columns subjected to dynamic loading condition by comparing with the corresponding individual columns made of single material (aluminum column and WF‐CFRP column). The dynamic axial crushing tests indicate that specific energy absorption of WF‐CFRP column is 45% higher than that of the aluminum column and 27% superior to that of the hybrid column, while the total energy absorption of the hybrid column is about 8% higher than the summation of WF‐CFRP column and aluminum column. Afterward, several finite element models are developed to reveal the underlying energy‐absorbing mechanisms and the influences of each factor for the hybrid columns. The numerical results show that specific energy absorption of the hybrid columns is negatively correlated with the metal volume fraction (F m), when inner aluminum wall thickness (t m) equals to 1.0 mm. It is also found that crushing process of the hybrid columns with l = 2 (2 CFRP layers) is dominated by the progressive folding of inner aluminum column, leading to a lower damage level of CFRP and lower load carrying capacity. With increasing wrapped CFRP layer number up to 8, the inner aluminum column starts to generate internal inversion deformation mode due to the restriction of the outer CFRP layers, and outer CFRP layers exhibit progressive failure. The energy‐absorbing mechanisms analysis indicates that the internal energy of the internally inversed aluminum column is significantly higher than that of the progressively folded aluminum column, and thus such special deformation mode is capable to offer a more stable and higher load carrying capacity for the hybrid columns. Besides, it is also found that the plastic deformation of the inner aluminum column is the major energy‐absorbing mechanism, which is followed by the crushing failure of outer CFRP layers. The combination mode of thinner aluminum column and thicker CFRP layers tends to offer higher energy‐absorbing capacity, which is much higher than that of the summation of corresponding individual columns. Finally, a complex proportional assessment method is considered to select the optimal configuration achieving the balance of material cost and structural crashworthiness. The present study is expected to provide guideline for design of metal/CFRP hybrid columns.

Crashworthiness analysis and multi‐objective optimization of Al/CFRP tubes with induced holes

“…Researchers have conducted extensive research on this hybrid structure. [9][10][11][12][13][14][15][16] In recent research, Sun et al [17,18] and Zhu et al, [19][20][21] explored experimentally and numerically the crushing characteristics involving EA and damage behaviors of Al/CFRP hybrid tubes, proving that Al/CFRP structure is a class of promising cost-effective lightweight structure. In addition, Sun et al [22] also studied the failure behavior and EA capacity of Al/CFRP hybrid tube under bending load, and found that the two hybrid forms (the CFRP tube being placed outside the Al tube and the CFRP tube being placed inside the Al tube) have better crashworthiness.…”

Study on the axial impact of Al‐CFRP thin‐walled tubes with induced design

“…In this study, several commonly used indicators were used to evaluated the crashworthiness of Al‐CFRP hybrid tubes, which include energy absorption (EA), peak load ( F max ), specific energy absorption (SEA), average load ( F mean ), and load efficiency (CFE). [ 20 ] The specific definitions of these indicators are as follows: F max is the peak value of the load displacement curve, and EA is the area under the force displacement curve under a given loading displacement. F mean is the ratio of EA to loading displacement ( F mean = EA/), and CFE is the ratio of F mean to F max (CFE = F mean / F max ).…”

“…A large number of researchers are increasingly using numerical simulation to carry out research, and numerical results show that multi-layer modeling technology has higher accuracy. [17,18] Zhu et al [18] explored the energy absorption characteristics of aluminum/carbon fiber composites under oblique quasistatic load and axial impact load [19,20] by combining experimental and simulation methods. Emadi et al [21] studied the relationship between Al thickness and composite material thickness by combining experiment and simulation, which has a good guiding significance for the design of composite tube.…”

“…Emadi et al [ 32 ] used finite element (FE) simulation and multi‐objective optimization methods to design the crashworthiness of Al‐CFRP hybrid tubes, and studied the influence of metal volume fraction on the crash‐resistance of hybrid tubes. In addition, Zhu et al [ 20 ] used COPRAS method in the crashworthiness design of al‐CFRP hybrid thin‐walled tubes in order to select the optimal configuration to achieve a balance between material cost and structural crashworthiness. Considering the discreteness of design variables, Li et al [ 30 ] used discrete optimization method combined with orthogonal array method to determine the optimal configuration of foam‐filled aluminum/carbon fiber composite tube.…”

Deformation and energy absorption characters of Al‐CFRP hybrid tubes under quasi‐static radial compression

“…Therefore, more and more scholars have studied the mixing form of composite materials with metal and other materials, which is mainly to make the mixed structure deform in a stable and controllable way. [12][13][14][15][16] Yan et al [17] studied the radial crushing of empty and polyurethane-foam filled natural flax fabric reinforced epoxy composite tubes, and the results showed that the radial compression performance of the foam filled flax/ epoxy tube was improved compared with the same size empty tube and polyurethane-foam tube. Liu et al [18] investigated the radial planar crushing and bending responses of CFRP square tube filled with aluminum honeycomb by experimental and numerical methods.…”