Impact Damage Monitoring in Composite Plates

2004 ◽  
Author(s):  
Frank J. Shih ◽  
Sauvik Banerjee ◽  
Ajit K. Mal
Keyword(s):  
Impact Load ◽  
Impact Damage ◽  
Composite Plates ◽  
Impact Testing ◽  
Far Field ◽  
Internal Damage ◽  
Distributed Sensors ◽  
Surface Motion ◽  
Impact Monitoring ◽  
The Impact

This paper is concerned with the real-time detection of internal damage in composite structural components during impact using the far-field surface motion generated by these events. Impact tests are carried out on graphite epoxy composite plates using an instrumented impact testing system. Contact force and surface motion are measured at several locations on the plate surface. The far-field surface motions, both flexural and extensional waves in the composite plate, are modeled using both approximate and exact solution methods. Postimpact test were performed to determine the extent of internal damage caused by the impact load. Further research on the detection method can lead to the development of a viable impact monitoring system for composite aerospace structures using distributed sensors.

Detection of Impact Damage in Composite Plates Using Surface Contact Method

2006 ◽  
Vol 326-328 ◽  
pp. 1693-1696
Author(s):  
Heoung Jae Chun ◽  
Dang Won Kim ◽  
Joon Hyung Byun
Keyword(s):  
Composite Structures ◽  
Lamb Waves ◽  
Impact Damage ◽  
Incident Angle ◽  
Composite Plates ◽  
Wave Form ◽  
Contact Method ◽  
Internal Damage ◽  
Fundamental Causes ◽  
The Impact

It is a well known fact that the fundamental causes of most failures in composite structures are in the forms of incipient damages such as delaminations and cracks which usually remain undetected until they grow to levels large enough to cause failure. In this study, unidirectional carbon/epoxy composite plates with known defects are investigated. The known defects are generated by impacting the composite specimens simulating external collision. A pair of transmitter and receiver was used for generation of Lamb waves and reception of signals. The received signals were monitored by scanning the receiver toward internal defect or by scanning both transmitter and receiver with confined distance over the surface of the composite plates which have known defects lie beneath them. The proper selection of incident angle and frequency are also considered. The characteristics of received signals such as amplitude, energy and wave form are analyzed. The acquired information is used to locate and to measure the size of the impact damage. The suggested method is very effective if the internal damage is presented closed to surface of the plate where the conventional pulse-echo method has problems. The proposed technique can be used widely for the real time and online monitoring of composite structures.

A Study on Low Velocity Impact of Woven Glass/Phenolic Composite Laminates Considering Environmental Effects

2005 ◽  
Vol 297-300 ◽  
pp. 1303-1308 ◽  
Author(s):  
Jae Hoon Kim ◽  
Duck Hoi Kim ◽  
Hu Shik Kim ◽  
Byoung Jun Park
Keyword(s):  
Compressive Strength ◽  
Environmental Effects ◽  
Impact Loading ◽  
Composite Laminates ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Internal Damage ◽  
The Impact ◽  
Phenolic Composite

The objectives of this study are to evaluate the internal damage and compressive residual strength of composite laminate by impact loading. To investigate the environmental effects, as-received and accelerated-aged glass/phenolic laminates are used. UT C-Scan is used to determine the impact damage characteristics and CAI tests are carried out to evaluate quantitatively the reduction of compressive strength by impact loading. The damage modes of the woven glass/phenolic laminates are evaluated. In the case of the accelerated-aged laminates, as aging time increases, initial failure energy and residual compressive strength decrease.

Impact Damage and Strength Reduction Behavior of Honeycomb Sandwich Structure Subjected to Low Velocity Impact

2006 ◽  
Vol 306-308 ◽  
pp. 279-284
Author(s):  
Ki Weon Kang ◽  
Jung Kyu Kim ◽  
Heung Seob Kim
Keyword(s):  
Sandwich Structure ◽  
Impact Damage ◽  
Testing Machine ◽  
Strength Reduction ◽  
Impact Testing ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Reduction Behavior ◽  
Velocity Impact ◽  
The Impact

The goals of the paper are to identify the impact damage and strength reduction behavior of sandwich structure, composed of carbon/epoxy laminates skin and Nomex core with two kinds of thickness (10 and 20mm). For these, low velocity impact tests were conducted using the instrumented impact-testing machine and damages are inspected by SAM. And then, subsequent static tests are conducted under flexural loading to identify the strength reduction behavior of the impacted sandwich structures. The impact damages are mainly delamination in carbon/epoxy skin and their behavior is mostly independent of core thickness. Also, their energy absorbing behavior is identified through calculating the energy absorbed by impact damage. Finally, the strength reduction behavior is evaluated through Caprino’s model, which was proposed on the unidirectional laminates.

Vibration Propagation Law and Control Test of Ultra Soft Soil Ground under Impact Load

2013 ◽  
Vol 295-298 ◽  
pp. 2030-2033
Author(s):  
Zhang Ming Li ◽  
Wen Xiu Zeng
Keyword(s):  
Impact Load ◽  
Soft Soil ◽  
Near Field ◽  
Far Field ◽  
Horizontal Distance ◽  
Negative Power ◽  
Propagation Law ◽  
Safe Control ◽  
The Impact ◽  
Control Distance

Through in situ tests on the impact vibration of a typical muck ground treatment major project directed by the first author, the vibration propagation law under the impact load for the ultra soft soil ground is obtained, and quantitative environmental safe control distance on the vibration influence is also gained. The main results are the two aspects. (1) The attenuation law of both level and vertical peak vibration acceleration with the horizontal distance can be described well by the negative power function; and the ground vibrations caused by tamping impact can be distinguished between two types, i.e. near-field and far-field. Near-field tamping vibration influence is confined to a small range of the tamping center, which decays obviously faster than the one of far-field. (2) The radius of influence of tamping vibration depends not only on the tamping energy but also the soil type. Loose, slightly dense soft soil has a larger energy absorption capacity and a smaller effect radius of tamping vibration than the dense and hard soil; and the vibration safe control distance is determined as 27.3m in the tests according to the safe boundary determined code of industrial and civil architecture in China.

scholarly journals Modeling Analysis of Guided Ultrasonic Waves in Composite Plates with Impact Damage

2018 ◽  
Vol 7 (4.26) ◽  
pp. 175
Author(s):  
Noorfaten Asyikin Ibrahim ◽  
Bibi Intan Suraya Murat
Keyword(s):  
Composite Structures ◽  
Impact Damage ◽  
Composite Plates ◽  
Guided Wave ◽  
Ultrasonic Waves ◽  
Fe Model ◽  
Element Analysis ◽  
Damage Area ◽  
Guided Ultrasonic Waves ◽  
The Impact

This paper investigates the propagation of guided ultrasonic waves and the interaction with impact damage in composite plates using a full three-dimensional Finite Element analysis. Impact damage in the composite plate was modeled as rectangular- and T-shaped delaminations. In order to provide guidelines for extending the modeling of realistic multimode impact damage, the impact damage was modeled as a combination of the delamination and reduced materials properties. The information obtained from these methods was compared to the experimental results around the damage area for a validation. There was a reasonable similarity between the experimental and FE results. The FE simulations can effectively model the scattering characteristics of the A0 mode wave propagation in anisotropic composite plates. This suggests that the simplified and easy-to-implement FE model could be used to represent the complex impact damage in composite plates. This could be useful for the improvement of the FE modeling and performance of guided wave methods for the in-situ NDE of large composite structures. 

scholarly journals Investigation on the Application of Taylor Impact Test to High-G Loading

2021 ◽  
Vol 8 ◽  
Author(s):  
Li Juncheng ◽  
Chen Gang ◽  
Lu Yonggang ◽  
Huang Fenglei
Keyword(s):  
Pulse Duration ◽  
Impact Loading ◽  
Impact Test ◽  
Impact Load ◽  
Low Cost ◽  
Large Mass ◽  
Impact Testing ◽  
Taylor Impact ◽  
Taylor Impact Test ◽  
The Impact

Taylor impact test is characterized by high impact energy, low cost, and good repeatability, giving it the technical foundation and development potential for application in high-g loading. In this paper, the feasibility of performing high-g load impact testing to a missile-borne recorder by conducting Taylor impact test was studied by combining simulation analyses with experimental verification. Acccording to the actual dimensions of the missile-borne recorder, an experimental piece was designed based on the Taylor impact principle. The impact loading characteristics of the missile-borne recorder were then simulated and analyzed at different impact velocities. In addition, the peak acceleration function and the pulse duration function of the load were fitted to guide the experimental design. A Taylor-Hopkinson impact experiment was also conducted to measure the impact load that was actually experienced by the missile-borne recorder and the results were compared with the results of strain measurements on the Hopkinson incident bar. The results showed that the peak value of impact load, the pulse duration and the waveform of the actual experimental results were in good agreement with the results predicted by the simulations. Additionally, the strain data measured on the incident bar could be used to verify or replace the acceleration testing of the specimen to simplify the experimental process required. Based on the impact velocity, high-g loading impact was achieved with peak values in the 7,000–30,000 g range and durations of 1.3–1 ms, and the waveform generated was a sawtooth wave. The research results provide a new approach for high amplitude and long pulse duration impact loading to large-mass components, and broaden the application field of Taylor impact test.

scholarly journals DYNAMIC IMPACT WEAR AND IMPACT RESISTANCE OF W-B-C COATINGS

2020 ◽  
Vol 27 ◽  
pp. 37-41
Author(s):  
Josef Daniel ◽  
Jan Grossman ◽  
Vilma Buršíková ◽  
Lukáš Zábranský ◽  
Pavel Souček ◽  
...  
Keyword(s):  
Impact Test ◽  
Impact Load ◽  
Protective Coatings ◽  
Impact Resistance ◽  
Impact Testing ◽  
The Novel ◽  
Test Results ◽  
Dynamic Impact ◽  
Impact Deformation ◽  
The Impact

Coated components used in industry are often exposed to repetitive dynamic impact load. The dynamic impact test is a suitable method for the study of thin protective coatings under such conditions. Aim of this paper is to describe the method of dynamic impact testing and the novel concepts of evaluation of the impact test results, such as the impact resistance and the impact deformation rate. All of the presented results were obtained by testing two W-B-C coatings with different C/W ratio. Different impact test results are discussed with respect to the coatings microstructure, the chemical and phase composition, and the mechanical properties. It is shown that coating adhesion to the HSS substrate played a crucial role in the coatings’ impact lifetime.

Event Driven Networked Control System for Impact Load Monitoring

2015 ◽  
Vol 237 ◽  
pp. 169-174
Author(s):  
Andrzej Majcher
Keyword(s):  
Control System ◽  
Impact Load ◽  
Networked Control System ◽  
Networked Control ◽  
Impact Monitoring ◽  
Event Driven ◽  
Load Monitoring ◽  
Properties Of Materials ◽  
Stochastic Characteristics ◽  
The Impact

The article describes the application of the event-driven networked control system (NCS) for impact load monitoring. The main problem in this type of application is measurement synchronization, which should provide full information about the impact in terms of stochastic delays introduced by the network and stochastic characteristics of the actuator. Using the simulation model of the NCS system, the method of solving this particular problem was developed. The results of verification tests for the real object and a synchronized dynamic measurement of signals from resistance strain gauges are presented. The described system can find use in monitoring and fault detection, in tasks connected with dynamics of liquids and gases, acoustics, and the analysis of resistance properties of materials and technical objects. Key words: Networked control system (NCS), event maintenance, event synchronization, impact monitoring, measurement trigger, strain gauge.

Impact Response and Simulation of Damaged Ulna With Internal Fixation

2012 ◽  
Vol 28 (3) ◽  
pp. 324-334
Author(s):  
Cameron Coates ◽  
Priya Goeser ◽  
Camille Coates-Clark ◽  
Mark Jenkins
Keyword(s):  
Impact Test ◽  
Impact Load ◽  
Impact Damage ◽  
Dynamic Compression ◽  
Dynamic Strain ◽  
Fe Model ◽  
Transverse Impact ◽  
Case Scenario ◽  
Worst Case ◽  
The Impact

The objectives of this work were to explore a methodology that combines static and dynamic finite element (FE) analysis, linear elastic fracture mechanics (LEFM) and experimental methods to investigate a worst-case scenario in which a previously damaged bone plate system is subjected to an impact load. Cadaver ulnas with and without midshaft dynamic compression plates are subjected to a static three-point bend test and loaded such that subcritical crack growth occurs as predicted by a hybrid method that couples LEFM and static FE. The plated and unplated bones are then unloaded and subsequently subjected to a midshaft transverse impact test. A dynamic strain-based FE model is also developed to model the midshaft transverse impact test. The average value of the impact energy required for failure was observed to be 10.53% greater for the plated set. There appears to be a trade-off between impact damage and impact resistance when ulnas are supported by fixation devices. Predictions from the dynamic FE model are shown to corroborate inferences from the experimental approach.

Study on damage behavior of carbide tool for milling difficult-to-machine material

2018 ◽  
Vol 233 (2) ◽  
pp. 735-747
Author(s):  
Yao-Nan Cheng ◽  
Wan-Ying Nie ◽  
Rui Guan ◽  
Wei-Kun Jia ◽  
Fu-gang Yan
Keyword(s):  
Failure Modes ◽  
Impact Load ◽  
Impact Damage ◽  
High Plasticity ◽  
Carbide Tool ◽  
Machine Material ◽  
Tool Failure ◽  
Damage Behavior ◽  
Tool Damage ◽  
The Impact

Water chamber head is an important component of nuclear power unit, and the main material is 508 III steel of difficult-to-machine material, which has the characteristics of high hardness, high strength, high plasticity and high profile shrinkage, etc. During the milling process, the tool is subjected to the cyclic impact load, which make cutting force and cutting heat change violent and occurrence of tool damage failure accelerate. In this paper, the damage behavior of carbide tool for milling difficult-to-machine material is studied first, and then field experiment was carried out on 508 III steel material, tool failure modes were analyzed, which include impact damage and fatigue fracture, and the failure theory and the crack propagation of carbide material were investigated in the process of tool damage. Then, the impact damage model of carbide tool is established based on the classical strength theory, and the critical condition of impact damage is determined according to simulation analysis. Finally, the theoretical model of carbide tool fatigue life is established and the tool fatigue limit is analyzed. Theoretical basis and technical support are provided for the tool failure mechanisms analysis, life prediction, parameter optimization, tool design and development aspects during the study.

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