An extended phantom node method study of crack propagation of composites under fatigue loading

2016 ◽  
Vol 154 ◽  
pp. 410-418 ◽  
Author(s):  
Chen Wang ◽  
Xiwu Xu
Keyword(s):  
Crack Propagation ◽  
Fatigue Loading ◽  
Phantom Node Method

scholarly journals Mode I Crack Propagation Experimental Analysis of Adhesive Bonded Joints Comprising Glass Fibre Composite Material under Impact and Constant Amplitude Fatigue Loading

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4380
Author(s):  
Alirio Andres Bautista Villamil ◽  
Juan Pablo Casas Rodriguez ◽  
Alicia Porras Holguin ◽  
Maribel Silva Barrera
Keyword(s):  
Crack Propagation ◽  
Structural Integrity ◽  
Crack Propagation Rate ◽  
Fatigue Loading ◽  
Propagation Rate ◽  
Operating Conditions ◽  
Impact Testing ◽  
Mode I ◽  
Mode I Crack ◽  
Constant Amplitude

The T-90 Calima is a low-wing monoplane aircraft. Its structure is mainly composed of different components of composite materials, which are mainly bonded by using adhesive joints of different thicknesses. The T-90 Calima is a trainer aircraft; thus, adverse operating conditions such as hard landings, which cause impact loads, may affect the structural integrity of aircrafts. As a result, in this study, the mode I crack propagation rate of a typical adhesive joint of the aircraft is estimated under impact and constant amplitude fatigue loading. To this end, effects of adhesive thickness on the mechanical performance of the joint under quasistatic loading conditions, impact and constant amplitude fatigue in double cantilever beam (DCB) specimens are experimentally investigated. Cyclic impact is induced using a drop-weight impact testing machine to obtain the crack propagation rate (da/dN) as a function of the maximum strain energy release rate (GImax) diagram; likewise, this diagram is also obtained under constant amplitude fatigue, and both diagrams are compared to determine the effect of each type of loading on the structural integrity of the joint. Results reveal that the crack propagation rate under impact fatigue is three orders of magnitude greater than that under constant amplitude fatigue.

The Behavior of Tiled Laminate GFRP Composites, a Class of Robust Materials for Civil Applications

2019 ◽  
Author(s):  
Wouter De Corte ◽  
Jordi Uyttersprot ◽  
Wim Van Paepegem
Keyword(s):  
Crack Propagation ◽  
Numerical Simulations ◽  
Bridge Deck ◽  
Fatigue Loading ◽  
Structural Behavior ◽  
Gfrp Composites ◽  
Civil Structures ◽  
Laminate Composites ◽  
Deck Panels ◽  
Highly Loaded

<p>This paper focuses on the structural behavior of tiled laminate composites. Such laminates, in which the plies are not parallel to the outer surfaces are found in GFRP bridge deck panels. The technology is developed for the construction of robust GFRP panels useful in highly loaded structures such as bridges or lock gates. In civil structures, the drawback in traditional FRP sandwich structures has always been debonding of skin and core. Such a debonding problem may occur after unintentional impact, followed by fatigue loading. Through the concept of using overlapping Z-shaped and two-flanged web laminates, alternating with polyurethane foam cores, debonding is no longer possible in vacuum infused GFRP bridge deck panels. In such panels, the fibers in the upper and lower skins as well as in the vertical webs run in all directions, rendering a resin-dominated crack propagation impossible. As a result of the integration of core and skin reinforcement, a skin material is created in which the reinforcement is not parallel to the outer surfaces, but tiled. Based on experimental results and numerical simulations the relevance of tiled laminates for civil applications is demonstrated.</p>

Fatigue Crack Modeling and Simulation Based on Continuum Damage Mechanics

2006 ◽  
Vol 129 (1) ◽  
pp. 96-102 ◽  
Author(s):  
Masakazu Takagaki ◽  
Toshiya Nakamura
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Fatigue Crack Propagation ◽  
Damage Mechanics ◽  
Low Cycle Fatigue ◽  
Continuum Damage Mechanics ◽  
Fatigue Loading ◽  
Present Theory ◽  
Continuum Damage ◽  
Cycle Fatigue

Numerical simulation of fatigue crack propagation based on fracture mechanics and the conventional finite element method requires a huge amount of computational resources when the cracked structure shows a complicated condition such as the multiple site damage or thermal fatigue. The objective of the present study is to develop a simulation technique for fatigue crack propagation that can be applied to complex situations by employing the continuum damage mechanics (CDM). An anisotropic damage tensor is defined to model a macroscopic fatigue crack. The validity of the present theory is examined by comparing the elastic stress distributions around the crack tip with those obtained by a conventional method. Combined with a nonlinear elasto-plastic constitutive equation, numerical simulations are conducted for low cycle fatigue crack propagation in a plate with one or two cracks. The results show good agreement with the experiments. Finally, propagations of multiply distributed cracks under low cycle fatigue loading are simulated to demonstrate the potential application of the present method.

Mechanical performance and crack retardation study of a fiberglass-grid-reinforced asphalt concrete system

2008 ◽  
Vol 35 (10) ◽  
pp. 1042-1049 ◽  
Author(s):  
S. Joon Lee
Keyword(s):  
Crack Propagation ◽  
Asphalt Concrete ◽  
Mechanical Performance ◽  
Fatigue Loading ◽  
Cyclic Fatigue ◽  
Mechanical Tests ◽  
Flexural Stress ◽  
Acrylic Polymer ◽  
Road Testing ◽  
Cracking Pattern

This paper presents constitutive design considerations for a semi-rigid, resin-impregnated fiberglass grid that enhances the mechanical performance of an asphalt concrete overlay and provides a pattern to retard crack propagation. An acrylic polymer resin covers the grid-structured fiberglass strands, thus making their viscoelastic nature compatible with the asphalt materials. The remarkable temperature susceptibility of the resin is observed using time–temperature superposition. The grid tensile strength of 100 kN/m was qualified using standard measurements. Three-point bending and cyclic fatigue loading mechanical tests affirm the retardation performance of the grid-reinforced system in terms of crack propagation. The retardation mechanism is affected by synchronizing the cracking pattern with the flexural stress–strain profile through image analysis. A National Center for Asphalt Technology full-scale road testing program provides assessment of the grid-reinforced pavements. A visual inspection of the grid extracted from the traffick zone showed fair condition of the pavement.

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