scholarly journals Numerical Simulation of Crack Propagation of Architecture Glass Under Explosion and Impact Load

2021 ◽  
Author(s):  
Mufei Wang ◽  
Zhiqiang Li
Keyword(s):  
Crack Propagation ◽  
Solid Mechanics ◽  
Impact Load ◽  
Crack Growth Behavior ◽  
Failure Behavior ◽  
Low Velocity ◽  
Critical Energy Release Rate ◽  
Propagation Behavior ◽  
Crack Propagation Behavior ◽  
Crack Bifurcation

Abstract Crack initiation and propagation is a long-standing difficulty in solid mechanics, especially for elastic-brittle material. To explore the damage and crack propagation behavior of architectural glass under different type of loads, the element deletion (ED), discontinuous Galerkin peridynamics (DG-PD) and meshless peridynamics (M-PD) methods are studied. Taking the architecture glass as an example, the crack propagation behavior under the bullet impact and explosion load are studied. The JH-2 material model is used in the ED method, and the maximum principal stress and maximum principal strain failure criteria are applied at the same time. In the DG-PD method, it conducts a node separation operation and imposes the criterion of the critical energy release rate. The M-PD method adopts a self-programmed particle discretization method and imposes a criterion of critical elongation. Three methods can simulate the crack growth behavior of glass material, but the PD method has great advantages in detail, such as crack bifurcation and penetration. For low-velocity bullets, the failure behavior of glass all shows cross-shaped cracks in different methods. The splashing of elements or particles appears in the two PD methods, but the particle splashing of the M-PD method is more obvious, and the DG-PD method captures the crack bifurcation effect better. For the failure behavior of glass under explosive loading, the PD method is obviously better than the ED method in terms of modal appearance. However, in the mechanical behavior of specific elements, the two methods have a high degree of agreement.

CRACK PROPAGATION BEHAVIOR OF LATERALLY CONSTRAINED POLYMERS USED AS DIELECTRIC ELASTOMERS

2021 ◽  
Author(s):  
Dilshad Ahmad ◽  
Karali Patra ◽  
Mokarram Hossain ◽  
Amit Kumar
Keyword(s):  
Crack Propagation ◽  
Crack Tip ◽  
Propagation Speed ◽  
Dielectric Elastomers ◽  
Failure Behavior ◽  
Strain Rates ◽  
Propagation Behavior ◽  
Average Crack ◽  
Crack Propagation Speed ◽  
Crack Propagation Behavior

ABSTRACT Dielectric elastomer-based transducers are rapidly gaining importance with the syntheses of new polymers that can potentially be used as dielectric materials. However, these materials are always prone to fracture in the presence of cracks and flaws. Failures originate from flaws (or notches), and a complete fracture may take place due to the propagation of cracks. The present work investigates the crack propagation behavior of two popular polymers, VHB 4910 and Ecoflex, that are widely used as dielectric elastomers. In this case, tensile loadings in laterally constrained boundary conditions are considered. The average crack propagation speed for Ecoflex is higher than that for VHB, implying that Ecoflex will fail earlier than that of VHB under similar conditions. Moreover, with increasing notch lengths at a fixed strain rate, the average crack propagation speed decreases appreciably but becomes constant for comparatively larger notches. The results also conclude that the average crack propagation speed and normalized crack tip diameter remain higher for VHB than for Ecoflex for larger normalized notch lengths. It is observed that the average crack propagation speed increases with strain rates, whereas the normalized crack tip diameter is independent of strain rates. Experimental results obtained here will provide a useful comparative insight to understand the failure behavior of two polymers widely used as dielectric elastomers.

The Effect of Cement Line Properties and Crack Orientation on Crack Propagation in Cortical Bone

2009 ◽  
Author(s):  
Susan Mischinski ◽  
Ani Ural
Keyword(s):  
Crack Propagation ◽  
Cortical Bone ◽  
Crack Growth Behavior ◽  
Crack Orientation ◽  
Cement Line ◽  
Propagation Behavior ◽  
Complete Failure ◽  
Cement Lines ◽  
Underlying Mechanisms ◽  
Crack Propagation Behavior

Microstructural features such as osteons and cement lines are considered to play an important role in determining the crack growth behavior in cortical bone. Cracks that penetrate the osteons may lead to complete failure of the bone [1]. On the other hand, the cracks that are deflected into the cement line slow down the crack propagation and increase the crack resistance of the bone. Although various factors were reported in the literature [1–4], the underlying mechanisms of crack propagation behavior in cortical bone have not been completely understood.

scholarly journals Unique Slow Crack Growth Behavior of Isotactic Polypropylene: The Role of Shear Layer-Spherulites Layer Alternated Structure

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2746
Author(s):  
Mingjin Liu ◽  
Jiaxu Luo ◽  
Jin Chen ◽  
Xueqin Gao ◽  
Qiang Fu ◽  
...  
Keyword(s):  
Shear Layer ◽  
Crack Growth ◽  
Isotactic Polypropylene ◽  
Slow Crack Growth ◽  
Crack Growth Behavior ◽  
Polymer Science ◽  
The Past ◽  
Propagation Behavior ◽  
Crack Propagation Behavior

With the development of polymer science, more attention is being paid to the longevity of polymer products. Slow crack growth (SCG), one of the most important factors that reveal the service life of the products, has been investigated widely in the past decades. Here, we manufactured an isotactic polypropylene (iPP) sample with a novel shear layer–spherulites layer alternated structure using multiflow vibration injection molding (MFVIM). However, the effect of the alternated structure on the SCG behavior has never been reported before. Surprisingly, the results showed that the resistivity of polymer to SCG can be enhanced remarkably due to the special alternated structure. Moreover, this sample shows unique slow crack propagation behavior in contrast to the sample with the same thickness of shear layer, presenting multiple microcracks in the spherulites layer, which can explain the reason of the resistivity improvement of polymer to SCG.

scholarly journals Crack Propagation Behavior of a Ni-Based Single-Crystal Superalloy during In Situ SEM Tensile Test at 1000 °C

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1047
Author(s):  
Wenxiang Jiang ◽  
Xiaoyi Ren ◽  
Jinghao Zhao ◽  
Jianli Zhou ◽  
Jinyao Ma ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Tensile Test ◽  
Single Crystal ◽  
Crack Propagation Rate ◽  
Propagation Rate ◽  
Single Crystal Superalloy ◽  
Propagation Path ◽  
Propagation Behavior ◽  
Crack Propagation Behavior

An in situ scanning electron microscope (SEM) tensile test for Ni-based single-crystal superalloy was carried out at 1000 °C. The stress displacement was obtained, and the yield strength and tensile strength of the superalloy were 699 MPa and 826 MPa, respectively. The crack propagation process, consisting of Model I crack and crystallographic shearing crack, was determined. More interestingly, the crack propagation path and rate affected by eutectics was directly observed and counted. Results show that the coalescence of the primary crack and second microcrack at the interface of a γ/γ′ matrix and eutectics would make the crack propagation rate increase from 0.3 μm/s to 0.4 μm/s. On the other hand, crack deflection decreased the rate to 0.05 μm/s. Moreover, movement of dislocations in front of the crack was also analyzed to explain the different crack propagation behavior in the superalloy.

Crack propagation behavior of inhomogeneous laminated Ti−Nb metal−metal composite

2019 ◽  
Vol 29 (9) ◽  
pp. 1882-1888 ◽  
Author(s):  
Wen-juan CHENG ◽  
Yong LIU ◽  
Da-peng ZHAO ◽  
Bin LIU ◽  
Yan-ni TAN ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Metal Composite ◽  
Propagation Behavior ◽  
Metal Metal ◽  
Crack Propagation Behavior
Sign in / Sign up

Export Citation Format

Share Document