Characterization of the Bonded Connection in Hybrid-Steel-GFRP-Laminates

2017 ◽  
Vol 742 ◽  
pp. 408-415 ◽  
Author(s):  
Arne Busch ◽  
Robert Brandt

Intrinsic hybrid laminates are well established since many years in aerospace engineering, e.g. Glass Laminate Aluminium Reinforced Epoxy (GLARE) is widely used as a substitute for aluminium sheets of the outer shell of modern aircrafts. The reduction of density and an increased stiffness by compounding glass fiber and aluminium makes GLARE advantageous. Driven by environmental protection acts and the need for lightweight design material compounds attract more awareness in the automotive engineering as well. Functional components like chassis springs are well predestined for the application of glass fiber reinforced plastics (GFRP). Therefore, an intrinsic hybrid made up by GFRP and a high strength steel has recently been developed and characterized. This investigation sets the focus on the interface between GFRP and steel. Double cantilever beam tests (mode I) and shear tests (mode II) are conducted in order to measure the energy release rate and the shear strength of the considered interface. A variety of surface treatments of steel layer has been characterized by this approach. The results show up that good adhesion can be achieved by silane and titanium dioxide primers, however, the variation within the data is significantly higher than for other surface treatment variants. Furthermore, the increase of the energy release rate by fiber bridging effects is considered as well and an approach for its quantitative description by a power law is presented.

CIRP Annals ◽  
2011 ◽  
Vol 60 (1) ◽  
pp. 307-310 ◽  
Author(s):  
Rajiv Shivpuri ◽  
Siddarth Singh ◽  
Kuldeep Agarwal ◽  
Chun Liu

2018 ◽  
Vol 46 (3) ◽  
pp. 130-152
Author(s):  
Dennis S. Kelliher

ABSTRACT When performing predictive durability analyses on tires using finite element methods, it is generally recognized that energy release rate (ERR) is the best measure by which to characterize the fatigue behavior of rubber. By addressing actual cracks in a simulation geometry, ERR provides a more appropriate durability criterion than the strain energy density (SED) of geometries without cracks. If determined as a function of crack length and loading history, and augmented with material crack growth properties, ERR allows for a quantitative prediction of fatigue life. Complications arise, however, from extra steps required to implement the calculation of ERR within the analysis process. This article presents an overview and some details of a method to perform such analyses. The method involves a preprocessing step that automates the creation of a ribbon crack within an axisymmetric-geometry finite element model at a predetermined location. After inflating and expanding to three dimensions to fully load the tire against a surface, full ribbon sections of the crack are then incrementally closed through multiple solution steps, finally achieving complete closure. A postprocessing step is developed to determine ERR as a function of crack length from this enforced crack closure technique. This includes an innovative approach to calculating ERR as the crack length approaches zero.


Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 611
Author(s):  
Benshuai Chen ◽  
Guangchun Xiao ◽  
Mingdong Yi ◽  
Jingjie Zhang ◽  
Tingting Zhou ◽  
...  

In this paper, the Voronoimosaic model and the cohesive element method were used to simulate crack propagation in the microstructure of alumina/graphene composite ceramic tool materials. The effects of graphene characteristic size and volume content on the crack propagation behavior of microstructure model of alumina/graphene composite ceramics under different interfacial bonding strength were studied. When the phase interface is weak, the average energy release rate is the highest as the short diameter of graphene is 10–50 nm and the long diameter is 1600–2000 nm. When the phase interface is strong, the average energy release rate is the highest as the short diameter of graphene is 50–100 nm and the long diameter is 800–1200 nm. When the volume content of graphene is 0.50 vol.%, the average energy release rate reaches the maximum. When the velocity load is 0.005 m s−1, the simulation result is convergent. It is proven that the simulation results are in good agreement with the experimental phenomena.


Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2552 ◽  
Author(s):  
Uwe Gohs ◽  
Michael Mueller ◽  
Carsten Zschech ◽  
Serge Zhandarov

Continuous glass fiber-reinforced polypropylene composites produced by using hybrid yarns show reduced fiber-to-matrix adhesion in comparison to their thermosetting counterparts. Their consolidation involves no curing, and the chemical reactions are limited to the glass fiber surface, the silane coupling agent, and the maleic anhydride-grafted polypropylene. This paper investigates the impact of electron beam crosslinkable toughened polypropylene, alkylene-functionalized single glass fibers, and electron-induced grafting and crosslinking on the local interfacial shear strength and critical energy release rate in single glass fiber polypropylene model microcomposites. A systematic comparison of non-, amino-, alkyl-, and alkylene-functionalized single fibers in virgin, crosslinkable toughened and electron beam crosslinked toughened polypropylene was done in order to study their influence on the local interfacial strength parameters. In comparison to amino-functionalized single glass fibers in polypropylene/maleic anhydride-grafted polypropylene, an enhanced local interfacial shear strength (+20%) and critical energy release rate (+80%) were observed for alkylene-functionalized single glass fibers in electron beam crosslinked toughened polypropylene.


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