Investigation on Interfacial Bonding Strength of Anisotropic Conducive Adhesive with a New Cohesive Zone Model

2010 ◽  
Vol 654-656 ◽  
pp. 1928-1931
Author(s):  
Jun Zhang ◽  
Yong Cheng Lin ◽  
Xin Li Wei ◽  
Liu Gang Huang
Keyword(s):  
Bonding Strength ◽  
Cohesive Zone ◽  
Thermal Cycle ◽  
Cohesive Zone Model ◽  
Zone Model ◽  
Interface Model ◽  
Damage Factor ◽  
Adhesive Film ◽  
User Subroutine ◽  
Interfacial Bonding Strength

A modified cohesive zone interface model with a damage factor was proposed to describe the effects of the thermal cycle and humidity aging on the strengths of adhesive joints. The damage factor can not only change the cohesive zone bonding strength but also affect the energies of separation. The modified cohesive zone interfacial model, as a user subroutine, is developed and implemented in ABAQUS to simulate the 90° peeling process of the specimens, which were bonded by anisotropic conducive adhesive film (ACF) and subjected to the cycle and humidity aging tests. The numerical simulated results well agree with experimental results, which confirmed the validity of the new model.

A Damage Cohesive Model for Simulating 90° Peel Propagation in Anisotropic Conducive Adhesive Bonding

2010 ◽  
Vol 139-141 ◽  
pp. 374-377
Author(s):  
Jun Zhang ◽  
Zhong Yao Zhao ◽  
Xin Li Wei
Keyword(s):  
Cohesive Zone ◽  
Thermal Cycle ◽  
Adhesive Bonding ◽  
Bulk Material ◽  
Damage Factor ◽  
Quadrilateral Element ◽  
Adhesive Film ◽  
Cohesive Model ◽  
Material Element ◽  
Hourglass Control

A modified cohesive zone interface model that has a damage factor couple with the thermal cycle and humidity aging was proposed. The damage factor not only can change the cohesive zone strength acting but also can effect on the energies of separation. The modified cohesive zone interfacial model is developed and implemented in ABAQUS, as a user element subroutine, to simulate the peeling process for the specimen bonding by anisotropic conducive adhesive film (ACF) under the thermal cycle and humidity tests. Finite element explicit code and the constitutive relation of this element has been defined by the user-defined mechanical material behaviour (VUMAT). The bulk material element selected is a 4-node bilinear plane stress quadrilateral element, and the reduced integration and hourglass control are also adopted. The numerical simulated results accorded well to the experiments to illustrate the validity of the new model.

scholarly journals Ultrasonic Deicing Efficiency Prediction and Validation for a Flat Deicing System

2020 ◽  
Vol 10 (19) ◽  
pp. 6640
Author(s):  
Zhonghua Shi ◽  
Zhenhang Kang ◽  
Qiang Xie ◽  
Yuan Tian ◽  
Yueqing Zhao ◽  
...  
Keyword(s):  
Lead Zirconate Titanate ◽  
Cohesive Zone ◽  
Cohesive Zone Model ◽  
Lead Zirconate ◽  
Efficiency Factor ◽  
Zone Model ◽  
Shear Stresses ◽  
Stress Distributions ◽  
Total Energy Density ◽  
Average Shear

An effective deicing system is needed to be designed to conveniently remove ice from the surfaces of structures. In this paper, an ultrasonic deicing system for different configurations was estimated and verified based on finite element simulations. The research focused on deicing efficiency factor (DEF) discussions, prediction, and validations. Firstly, seven different configurations of Lead zirconate titanate (PZT) disk actuators with the same volume but different radius and thickness were adopted to conduct harmonic analysis. The effects of PZT shape on shear stresses and optimal frequencies were obtained. Simultaneously, the average shear stresses at the ice/substrate interface and total energy density needed for deicing were calculated. Then, a coefficient named deicing efficiency factor (DEF) was proposed to estimate deicing efficiency. Based on these results, the optimized configuration and deicing frequency are given. Furthermore, four different icing cases for the optimize configuration were studied to further verify the rationality of DEF. The effects of shear stress distributions on deicing efficiency were also analyzed. At same time, a cohesive zone model (CZM) was introduced to describe interface behavior of the plate and ice layer. Standard-explicit co-simulation was utilized to model the wave propagation and ice layer delamination process. Finally, the deicing experiments were carried out to validate the feasibility and correctness of the deicing system.

scholarly journals An Improved Cohesive Zone Model for Interface Mixed-Mode Fractures of Railway Slab Tracks

2021 ◽  
Vol 11 (1) ◽  
pp. 456
Author(s):  
Yanglong Zhong ◽  
Liang Gao ◽  
Xiaopei Cai ◽  
Bolun An ◽  
Zhihan Zhang ◽  
...  
Keyword(s):  
Interface Crack ◽  
Cohesive Zone ◽  
Mixed Mode ◽  
Cohesive Zone Model ◽  
Complex Loading ◽  
Bending Test ◽  
Mixed Mode Fracture ◽  
Zone Model ◽  
Slab Track ◽  
Interfacial Cracks

The interface crack of a slab track is a fracture of mixed-mode that experiences a complex loading–unloading–reloading process. A reasonable simulation of the interaction between the layers of slab tracks is the key to studying the interface crack. However, the existing models of interface disease of slab track have problems, such as the stress oscillation of the crack tip and self-repairing, which do not simulate the mixed mode of interface cracks accurately. Aiming at these shortcomings, we propose an improved cohesive zone model combined with an unloading/reloading relationship based on the original Park–Paulino–Roesler (PPR) model in this paper. It is shown that the improved model guaranteed the consistency of the cohesive constitutive model and described the mixed-mode fracture better. This conclusion is based on the assessment of work-of-separation and the simulation of the mixed-mode bending test. Through the test of loading, unloading, and reloading, we observed that the improved unloading/reloading relationship effectively eliminated the issue of self-repairing and preserved all essential features. The proposed model provides a tool for the study of interface cracking mechanism of ballastless tracks and theoretical guidance for the monitoring, maintenance, and repair of layer defects, such as interfacial cracks and slab arches.

Cohesive Zone Model for the Interface of Multiwalled Carbon Nanotubes and Copper: Molecular Dynamics Simulation

2014 ◽  
Vol 5 (3) ◽  
Author(s):  
Ibrahim Awad ◽  
Leila Ladani
Keyword(s):  
Carbon Nanotubes ◽  
Normal Stress ◽  
Multiwalled Carbon Nanotubes ◽  
Cohesive Zone ◽  
Large Scale ◽  
Cohesive Zone Model ◽  
Dynamics Simulation ◽  
Zone Model ◽  
Multiwalled Carbon ◽  
Significant Difference

Due to their superior mechanical and electrical properties, multiwalled carbon nanotubes (MWCNTs) have the potential to be used in many nano-/micro-electronic applications, e.g., through silicon vias (TSVs), interconnects, transistors, etc. In particular, use of MWCNT bundles inside annular cylinders of copper (Cu) as TSV is proposed in this study. However, the significant difference in scale makes it difficult to evaluate the interfacial mechanical integrity. Cohesive zone models (CZM) are typically used at large scale to determine the mechanical adherence at the interface. However, at molecular level, no routine technique is available. Molecular dynamic (MD) simulations is used to determine the stresses that are required to separate MWCNTs from a copper slab and generate normal stress–displacement curves for CZM. Only van der Waals (vdW) interaction is considered for MWCNT/Cu interface. A displacement controlled loading was applied in a direction perpendicular to MWCNT's axis in different cases with different number of walls and at different temperatures and CZM is obtained for each case. Furthermore, their effect on the CZM key parameters (normal cohesive strength (σmax) and the corresponding displacement (δn) has been studied. By increasing the number of the walls of the MWCNT, σmax was found to nonlinearly decrease. Displacement at maximum stress, δn, showed a nonlinear decrease as well with increasing the number of walls. Temperature effect on the stress–displacement curves was studied. When temperature was increased beyond 1 K, no relationship was found between the maximum normal stress and temperature. Likewise, the displacement at maximum load did not show any dependency to temperature.

Sign in / Sign up

Export Citation Format

Share Document