scholarly journals Theoretical and numerical investigation of the mode I delamination of composite laminate with uneven thickness

2021 ◽  
Author(s):  
Xiao Pan ◽  
Yi Jiang ◽  
Mingjun Li
Keyword(s):  
Composite Laminate ◽  
Peak Load ◽  
Fatigue Loading ◽  
Analysis Model ◽  
Model And Simulation ◽  
Instability Development ◽  
Simulation Based ◽  
Simulation And Experiment ◽  
Previous Loading ◽  
Delamination Behavior

In this paper, a theoretical analysis model and two simulation methods are applied to characterize the quasi-static and fatigue delamination of composite laminate with uneven thicknesses. The test data of partially reinforced double-cantilever beam (DCB) were used as benchmark to verify the analysis model and simulation, and cohesive zone models (CZMs) and virtual crack closure technique (VCCT) are used in simulation. It’s shown that the partially reinforced DCB has a unique double-peak load-displacement relationship, and produces instability development during the delamination. By comparing the results of simulation and experiment, it is found that the simulation based on the exponential CZM can simulate the delamination process of partially reinforced DCB under both quasi-static and fatigue loading; while VCCT method will generate a straight delamination front edge in the area of reinforcement, and lost the micro-damage of the previous loading step between load steps, and result in an incorrect delamination behavior.

Composite Laminate Delamination Simulation and Experiment: A Review of Recent Development

2018 ◽  
Vol 70 (3) ◽  
Author(s):  
Ala Tabiei ◽  
Wenlong Zhang
Keyword(s):  
Composite Laminate ◽  
Failure Modes ◽  
Cohesive Zone Model ◽  
Rapid Development ◽  
Fatigue Loading ◽  
Point Of View ◽  
Matrix Cracking ◽  
Zone Model ◽  
Simulation And Experiment ◽  
The Impact

Composite laminate has extensive usage in the aerospace and automotive industries. Thus delamination, one of its most prevalent and challenging failure modes, has attracted substantial research efforts, and lead to the rapid development of both simulation and experiment method. Although reviews exist about simulation and experiment methods, there are not many that cover the development in the last five years. This paper is targeted to fill that gap. We covered a broad range of topic in delamination, from the basic delamination onset and propagation theories to complex loading scenarios, like impact and fatigue loading. From a simulation point of view, virtual crack closure technique (VCCT) and cohesive zone model (CZM), the two most famous methods of delamination modeling, are compared and elaborated. Their implementation techniques are described, and their merits and drawbacks are discussed. We also covered the failure mode of combined delamination and matrix cracking, which is prevalent in impact loading scenarios. Simulation techniques, along with the failure mechanisms, are presented. From experiment point of view, the discussed topics range from delamination fracture toughness (DFT) tests under static, dynamic, or cyclic loading conditions, to impact tests that aim to obtain the impact resistance and residual strength after impact. Moreover, a collection of recent experiment data is provided.

scholarly journals A simulation-based optimisation approach to control nitrogen discharge by activated sludge under winter seasonal peak load

Water SA ◽  
2007 ◽  
Vol 32 (4) ◽  
Author(s):  
JM Choubert ◽  
Y Racault ◽  
A Grasmick ◽  
JP Canler Canler ◽  
A Heduit
Keyword(s):  
Activated Sludge ◽  
Peak Load ◽  
Seasonal Peak ◽  
Simulation Based ◽  
Nitrogen Discharge

scholarly journals Numerical Simulation of Long-Wave Infrared Generation Using an External Cavity Diamond Raman Laser

2021 ◽  
Vol 9 ◽  
Author(s):  
Hui Chen ◽  
Zhenxu Bai ◽  
Chen Zhao ◽  
Xuezong Yang ◽  
Jie Ding ◽  
...  
Keyword(s):  
Maximum Output Power ◽  
External Cavity ◽  
Raman Laser ◽  
Maximum Output ◽  
Analysis Model ◽  
Waist Size ◽  
Large Size ◽  
Long Wave ◽  
Model And Simulation ◽  
Long Wave Infrared

Diamond has a broad spectral transmission range (>0.2 μm) and the largest Raman frequency shift (1,332 cm−1) among known Raman crystals. Hence, the diamond Raman laser has the potential to achieve lasing in the long-wave infrared (LWIR) range, which is difficult to reach via other crystalline lasers. Here, we report a new approach to achieve LWIR output using diamond Raman conversion and provide the corresponding analysis model and simulation results. The conversion efficiency is analyzed as function of the pump waist size, output-coupler transmission, and crystal length, at constant pump power. The maximum output power at which a diamond of relatively large size can be operated without damage is predicted. This study paves a way for high-power LWIR lasing in diamond.

Combined Effects of Stress Concentration and Fatigue on the Reliability of Notched Laminates

2006 ◽  
Author(s):  
R. Ganesan ◽  
A. K. Arumugam
Keyword(s):  
Stress Concentration ◽  
Composite Laminates ◽  
Composite Laminate ◽  
Fatigue Loading ◽  
Stochastic Approach ◽  
Strength Properties ◽  
Combined Effect ◽  
Practical Reasons ◽  
Aerospace Applications ◽  
Structural Applications

Composite laminates are used in structural applications such as aircraft wings and tail structures. Drilling holes and making cutouts in these laminates are unavoidable for practical reasons. As a result, stress concentration is introduced near the hole or cutout, and the load-bearing capacity of the structure is reduced. In addition, composite laminates used in aerospace applications are subjected to considerable fatigue loading due to service conditions. In composite laminates, fatigue causes reduction in stiffness and strength. The objective of the present work is to study the combined effect of stress concentration and fatigue on the composite laminate. Since composite laminate displays significant variation in material and strength properties, the stress distribution in the laminate is stochastic in nature. It is more appropriate to analyze the notched composite laminates using a stochastic approach and to design the laminate based on a reliability-based design approach. In the present work, such an approach is developed and the combined effect of stress concentration and fatigue on the reliability of the laminate is investigated.

Effect of Fiber Lay-Up Direction Misalignment on the Natural Frequency of Composite Laminates

2010 ◽  
Vol 160-162 ◽  
pp. 65-70
Author(s):  
Zhen Yu Feng ◽  
Zhao Chen Chen ◽  
Jie Wen Hu ◽  
Qian Yang ◽  
Tian Chun Zou
Keyword(s):  
Natural Frequency ◽  
Composite Laminates ◽  
Composite Laminate ◽  
Natural Frequencies ◽  
Aviation Industry ◽  
Frequency Change ◽  
Vibration Modes ◽  
Analysis Model ◽  
Element Analysis ◽  
Finite Element Analysis Model

With the extensive use of composite materials in aviation industry, the research of factors which affect their basic performances in production and usage has become very important. In this paper, a finite element analysis model is built by the commercial software MSC.Nastran / Patran to research the effect of fiber lay-up direction misalignment on the natural frequency of composite laminates. The results show that, in the same boundary conditions, stacking sequence has a significant impact on the natural frequencies and vibration modes of composite laminates, and in the lay-up process, the natural frequency change of laminates caused by 0° fiber lay-up direction misalignment is much larger than the natural frequency change of laminates due to 90° fiber lay-up direction misalignment. In the process control and certification of composite laminate plates lay-up, special attention should be taken to the inspection of 0° direction fibers.

Tonsil tie simulator

2013 ◽  
Vol 127 (9) ◽  
pp. 924-926 ◽  
Author(s):  
J Duodu ◽  
T H J Lesser
Keyword(s):  
Blood Vessels ◽  
Low Pressure ◽  
Realistic Model ◽  
Surgical Skills ◽  
Operating Theatre ◽  
Active Bleeding ◽  
Surgical Trainee ◽  
Model And Simulation ◽  
Simulation Based ◽  
Training Opportunities

AbstractBackground:The surgical trainee has to acquire surgical skills in an era of reduced training hours and greater demands for efficient use of operating theatre time. Many surgical specialties are utilising model and simulation-based training to provide safe, low-pressure training opportunities for today's trainee.Method and results:This paper describes a simple, relatively inexpensive tonsillectomy model that enables the practice of tonsil removal and ligation of bleeding vessels. The model is beneficial for the patient, trainee and trainer.Conclusion:The pseudo mouth and active bleeding components of this model provide the trainee with a relatively inexpensive, realistic model with which to gain confidence and competence in the skill of ligating tonsillar blood vessels with a tonsil tie.

Sign in / Sign up

Export Citation Format

Share Document