Prediction of Crack Propagation under Dynamic Loading Conditions by Using the Enhanced Point Collocation Meshfree Method

2006 ◽  
Vol 324-325 ◽  
pp. 1059-1062
Author(s):  
Hyo Jin Kim ◽  
Sang Ho Lee ◽  
Moon Kyum Kim
Keyword(s):  
Crack Propagation ◽  
Dynamic Loading ◽  
Meshfree Method ◽  
Dynamic Loads ◽  
Dynamic Crack Propagation ◽  
Dynamic Crack ◽  
Loading Conditions ◽  
Point Collocation ◽  
Dynamic Loading Conditions ◽  
Numerical Program

An efficient and accurate numerical program with enhanced point collocation meshfree method is developed to simulate crack propagation under dynamic loading conditions. The enhanced meshfree method with point collocation formulation and derivative approximation in solids is presented. This study also presents the crack propagation criterion and computation of propagating direction, and the total structure of the numerical program named PCMDYC(Point Collocation Meshfree method for DYnamic Crack propagation). Several examples of crack propagation under dynamic loads are analyzed to simulate the arbitrary crack propagation under dynamic loads. The results show that PCMDYC predicts the propagating path of crack under dynamic loading conditions accurately and robustly.

Dynamic Crack Initiation And Growth In Cellulose Nanopaper

2021 ◽  
Author(s):  
Chengyun Miao ◽  
Haishun Du ◽  
Xinyu Zhang ◽  
Hareesh Tippur
Keyword(s):  
Crack Initiation ◽  
Crack Growth ◽  
Dynamic Loading ◽  
Image Correlation ◽  
Thin Strip ◽  
Dynamic Crack ◽  
Loading Conditions ◽  
Structural Applications ◽  
Cellulose Nanopaper ◽  
Dynamic Loading Conditions

Abstract Cellulose nanopaper (CNP) made of cellulose nanofibrils (CNF) has gained extensive attention in recent years for its lightweight and superior mechanical properties alongside sustainable and green attributes. The mechanical characterization studies on CNP at the moment have generally been limited to tension tests. In fact, thus far there has not been any report on crack initiation and growth behavior, especially under dynamic loading conditions. In this work, crack initiation and growth in self-assembled CNP, made from filtration of CNF suspension, are studied using a full-field optical method. Dynamic crack initiation and growth behaviors and time-resolved fracture parameters are quantified using Digital Image Correlation (DIC) technique. The challenge associated with dynamic loading of a thin strip of CNP has been overcome by an acrylic holder with a wide pre-cut slot bridged by edge-cracked CNP. The ultrahigh-speed digital photography is implemented to map in-plane deformations during pre- and post-crack initiation regimes including dynamic crack growth. Under stress wave loading conditions, macroscale crack growth occurs at surprisingly high-speed (600-700 m/s) in this microscopically fibrous material. The measured displacement fields from dynamic loading conditions are analyzed to extract stress intensity factors (SIF) and energy release rate (G) histories. The results show that the SIF at crack initiation is in the range of 6-7 MPa(m)1/2, far superior to many engineering plastics. Furthermore, the measured values increase during crack propagation under both low- and high-strain rates, demonstrating superior fracture resistance of CNP valuable for many structural applications.

Numerical Simulation on Fast Crack Propagation in a Bi-Material Involving interfaces under Dynamic Loading

2006 ◽  
Vol 324-325 ◽  
pp. 319-322
Author(s):  
Yue Sheng Wang ◽  
Jun Lei ◽  
Dietmar Gross
Keyword(s):  
Numerical Simulation ◽  
Crack Propagation ◽  
Boundary Element ◽  
Dynamic Loading ◽  
Time Domain ◽  
Domain Boundary ◽  
Dynamic Crack Propagation ◽  
Dynamic Crack ◽  
The Matrix ◽  
Good Agreement

The paper considers a bi-material with a crack propagating rapidly, penetrating or deflecting at the interface under dynamic loading. The hybrid time-domain boundary element method, together with the multi-region technique, is applied to simulate the dynamic process of propagation and penetration or deflection of the crack. Moving of the crack tip in the matrix, penetration and deflection of the crack at the interface, and propagation of the crack along the interface are controlled by criteria developed from the quasi-static ones. A bi-material rectangular plate with an edged crack under impact loading is computed and compared with the photoelastic experiments. Good agreement between numerical and experimental results implies that the present boundary element numerical method can provide an excellent simulation for the dynamic crack propagation in a bi-material involving interfaces.

Tensile and Fracture Characterization of PETI-5 and IM7/PETI-5 Graphite/Epoxy Composites Under Quasi-Static and Dynamic Loading Conditions

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Dongyeon Lee ◽  
Hareesh V. Tippur ◽  
Brian J. Jensen ◽  
Philip B. Bogert
Keyword(s):  
Dynamic Loading ◽  
Dynamic Fracture ◽  
Fracture Behavior ◽  
Matrix Material ◽  
Image Correlation ◽  
Dynamic Crack ◽  
Loading Conditions ◽  
Fiber Reinforced ◽  
Dynamic Loading Conditions ◽  
Static And Dynamic Loading

Tensile and fracture responses of the phenylethynyl terminated imide oligomer (PETI-5) are studied. Since this polymer is a candidate aerospace structural adhesive as well as a matrix material in composite systems, neat as well as fiber reinforced forms of PETI-5 are studied under static and dynamic loading conditions. A split-Hopkinson tension bar apparatus is used for performing tensile tests on dogbone specimens. The dynamic fracture tests are carried out using a drop tower in conjunction with 2D image correlation method and high-speed digital photography on edge cracked specimens in three-point bend configuration. A toughened neat epoxy system, Hexcel 3900, is also studied to provide a baseline comparison for neat PETI-5 system. The tensile stress-strain responses show PETI-5 to have excellent mechanical characteristics under quasi-static and dynamic loading conditions when compared with 3900. Fracture behavior of PETI-5 under quasi-static and impact loading conditions also shows superiority relative to 3900. The dynamic fracture behavior of a PETI-5 based graphite fiber reinforced composite, IM7/PETI-5, is also studied and the results are comparatively evaluated relative to the ones corresponding to a more common aerospace composite system, T800/3900-2 graphite/epoxy. Once again, the IM7/PETI-5 system shows excellent fracture performance in terms of dynamic crack initiation and growth behaviors.

Dynamic crack propagation in matrix involving inclusions by a time-domain BEM

2012 ◽  
Vol 36 (5) ◽  
pp. 651-657 ◽  
Author(s):  
Jun Lei ◽  
Yue-Sheng Wang ◽  
Yifeng Huang ◽  
Qingsheng Yang ◽  
Chuanzeng Zhang
Keyword(s):  
Crack Propagation ◽  
Time Domain ◽  
Dynamic Crack Propagation ◽  
Dynamic Crack

Dynamic Crack Propagation in Single-Crystalline Silicon

1998 ◽  
Vol 539 ◽  
Author(s):  
T. Cramer ◽  
A. Wanner ◽  
P. Gumbsch
Keyword(s):  
Crack Propagation ◽  
Crystalline Silicon ◽  
Potential Drop ◽  
Tensile Tests ◽  
Terminal Velocity ◽  
Dynamic Crack Propagation ◽  
Dynamic Crack ◽  
Single Crystalline Silicon ◽  
Single Crystalline ◽  
Crack Propagation Velocity

AbstractTensile tests on notched plates of single-crystalline silicon were carried out at high overloads. Cracks were forced to propagate on {110} planes in a <110> direction. The dynamics of the fracture process was measured using the potential drop technique and correlated with the fracture surface morphology. Crack propagation velocity did not exceed a terminal velocity of v = 3800 m/s, which corresponds to 83%7 of the Rayleigh wave velocity vR. Specimens fractured at low stresses exhibited crystallographic cleavage whereas a transition from mirror-like smooth regions to rougher hackle zones was observed in case of the specimens fractured at high stresses. Inspection of the mirror zone at high magnification revealed a deviation of the {110} plane onto {111} crystallographic facets.

Sign in / Sign up

Export Citation Format

Share Document