Cohesive Laws and Progressive Damage Analysis of Composite Bonded Joints, a Combined Numerical/Experimental Approach

Advanced polymeric composites are playing a major role in designing high-performance and lightweight vertical lift structures. However, uncertain residual strength and remaining useful life of the composite rotor and airframe structures due to complexity of failure mechanisms and susceptibility to manufacturing irregularities, which may be precursors to structural damage, impose risks that cannot be mitigated exclusively by time-consuming and costly experimental iterations. Validated analysis techniques accelerating design, certification, and qualification of composite structures are needed. Our team has been taking essential steps toward improving confidence in material qualification for laminated composites. The first step started with our reduced lamina test methods, short-beam shear, and small-plate twist based on digital image correlation measuring as a subset the standard material properties and, in addition, key properties that cannot be currently measured using any standard test methods. The lamina properties provide essential material input data for laminate analysis. The laminate analysis was the second step increasing confidence in material qualification. A known weakness of the existing progressive damage analysis methods is the lack of effective techniques to predict ultimate failure. The newly developed methodology relies on explicit finite element modeling and eliminates convergence issues in the ply-level progressive damage analysis methods due to severe nonlinear discontinuities after propagation of damage beyond detectable size. This work shows results of applying this methodology to nanosilica-toughened IM7/PMT-F3GHT open-hole tension strength/fatigue, open-hole compression strength/fatigue, and bearing strength multidirectional laminate configurations. The ability to predict progression of damage from initiation to ultimate strength and fatigue for advanced material systems including IM7/PMT-F3GHT carbon/epoxy reinforced by nanosilica has been demonstrated for the first time.

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Development of a Finite Element Model for Progressive Damage Analysis of Composite Laminates Subjected to Low Velocity Impact

Polymers and Polymer Composites ◽

10.1177/096739111402200111 ◽

2014 ◽

Vol 22 (1) ◽

pp. 73-78 ◽

Cited By ~ 1

Author(s):

Yuequan Wang ◽

Shuhua Zhu ◽

Junwei Qi ◽

Jun Xiao

Keyword(s):

Finite Element ◽

Finite Element Model ◽

Composite Laminates ◽

Element Model ◽

Low Velocity Impact ◽

Progressive Damage ◽

Damage Analysis ◽

Low Velocity ◽

Velocity Impact

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Progressive damage analysis of composite structures using higher-order layer-wise elements

Composites Part B Engineering ◽

10.1016/j.compositesb.2020.107921 ◽

2020 ◽

Vol 190 ◽

pp. 107921 ◽

Cited By ~ 5

Author(s):

M.H. Nagaraj ◽

J. Reiner ◽

R. Vaziri ◽

E. Carrera ◽

M. Petrolo

Keyword(s):

Composite Structures ◽

Higher Order ◽

Progressive Damage ◽

Damage Analysis

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Thermal Mismatch Effect and High-Temperature Tensile Performance Simulation of Hybrid CMC and Superalloy Bolted Joint by Progressive Damage Analysis

International Journal of Aerospace Engineering ◽

10.1155/2020/8739638 ◽

2020 ◽

Vol 2020 ◽

pp. 1-14

Author(s):

Shuyuan Zhao ◽

Jianglong Dong ◽

Chao Lv ◽

Zhengyu Li ◽

Xinyang Sun ◽

...

Keyword(s):

Thermal Expansion ◽

High Temperature ◽

Transportation Systems ◽

Bolted Joints ◽

Failure Behavior ◽

Progressive Damage ◽

Damage Analysis ◽

New Findings ◽

Tensile Performance ◽

High Temperature Tensile

The hybrid CMC and superalloy bolted joints have exhibited great potential to be used as thermostructural components of reusable space transportation systems, given the respective strengths of these two materials. In the high temperature excursion of the hybrid joints with the aircrafts and space vehicles, the substantial difference in thermal expansion coefficients of CMC and superalloy materials will induce complex superposition of initial assembly stress, thermal stress, and tensile stress around fastening area, which might lead to unknown failure behavior of joint structure. To address this concern, a finite element model embedded with progressive damage analysis was established to simulate the thermostructural behavior and high-temperature tensile performance of single-lap, single-bolt C/SiC composite and superalloy joint, by using the ABAQUS software. It was found that the initial stiffness of the CMC/superalloy hybrid bolted joints decreases with the rise of applied temperature under all bolt-hole clearance levels. However, the load-bearing capacity varies significantly with the initial clearance level and exposed temperature for the studied joint. The thermal expansion mismatch generated between the CMC and superalloy materials led to significant changes in the assembly preload and bolt-hole clearance as the high-temperature load is applied to the joint. The evolution in the thermostructural behavior upon temperature was then correlated with the variations in stiffness and failure load of the joints. The provided new findings are valuable for structural design and practical application of the hybrid CMC/superalloy bolted joints at high temperatures in next-generation aircrafts.

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