scholarly journals Modelling of Low-velocity Impacts on Composite Beams in Large Displacement

2021 ◽  
Vol 15 (58) ◽  
pp. 254-271
Author(s):  
Mattia Utzeri ◽  
Marco Sasso ◽  
Gianluca Chiappini ◽  
Stefano Lenci
Keyword(s):  
Analytical Model ◽  
Experimental Test ◽  
High Speed ◽  
Time History ◽  
Free Vibrations ◽  
Large Displacement ◽  
Low Velocity Impact ◽  
Lumped Mass ◽  
Low Velocity ◽  
The Impact

The paper provides an evaluation of the nonlinear dynamic response of a cantilever beam made of composite material subjected to low-velocity impacts. The structure is assumed to respond in a quasi-static manner and modelled by a continuous beam in large displacement with a lumped mass attached. First, an analytical model was developed to study the free vibrations of a beam, taking into account the nonlinearities due to large displacements and inertia. Then, the analytical findings were compared with experimental test data. The vibration of a real composite beam has been acquired through high-speed imaging technique. The displacements of the beam were extracted by digital image analysis; then, the nonlinear parameters of the analytical model were determined by the Fitting Time History technique. The results obtained by the analytical model and the experimental test are compared with numerical analysis. The validated analytical model was adapted to study a low-velocity impact; the lumped mass was associated with a rigid projectile, whose initial speed represents the impact velocity.

A Hierarchical Impact Force Reconstruction Method for Aerospace Composites

2019 ◽  
Vol 812 ◽  
pp. 17-24
Author(s):  
Mario Emanuele de Simone ◽  
Francesco Ciampa ◽  
Michele Meo
Keyword(s):  
Impact Force ◽  
Research Work ◽  
Time History ◽  
Low Velocity Impact ◽  
Reconstruction Method ◽  
Low Velocity ◽  
Force Reconstruction ◽  
Structural Responses ◽  
High Level ◽  
The Impact

This research work presents a hierarchical method able to reconstruct the time history of the impact force on a composite wing stringer-skin panel by using the structural responses measured by a set of surface bonded ultrasonic transducers. Time reversal method was used to identify the impact location by the knowledge of structural responses recorded from a set of excitation points arbitrarily chosen on the plane of the structure. Radial basis function interpolation approach was then used to calculate the transfer function at the impact point and reconstruct the impact force history. Experimental results showed the high level of accuracy of the proposed impact force reconstruction method for a number of low-velocity impact sources and energies.

ESTIMATION OF RESPONSE OF PLATE STRUCTURE SUBJECT TO LOW VELOCTIY IMPACT BY A SOLID OBJECT

2012 ◽  
Vol 12 (06) ◽  
pp. 1250053 ◽  
Author(s):  
Y. YANG ◽  
N. T. K. LAM ◽  
L. ZHANG
Keyword(s):  
Low Velocity Impact ◽  
Solid Object ◽  
Response Behavior ◽  
Lumped Mass ◽  
Low Velocity ◽  
Plate Structure ◽  
Novel Method ◽  
Lumped Masses ◽  
The Impact ◽  
Two Degree Of Freedom

This paper introduces the use of a two-degree-of-freedom (2DOF) model which comprises two spring-connected lumped masses for analyzing the response behavior of a plate structure to a low velocity impact of a flying solid object. We propose a novel method for calculating the value of the equivalent lumped mass and that of the spring constant which characterizes the 2DOF model. This is an important contribution given that existing calculation methods that are based on results from modal analysis would only be suitable for modeling the impact actions of wind or blast. Analysis involving the use of a 2DOF model is inexpensive and convenient to operate whilst achieving very good accuracies as demonstrated herein. By contrast, modeling impact response behavior by finite element analyses can be very time consuming and labour intensive because of the need to model in detail the impactor in contact with the target.

scholarly journals An analytical model for predicting permanent plastic deflection and strain distributions in aluminium-alloy plates under low velocity impact loading

2017 ◽  
Vol 232 (16) ◽  
pp. 2861-2872
Author(s):  
Jiangbo Bai ◽  
Junjiang Xiong ◽  
Ajit R Shenoi ◽  
Meng Liu
Keyword(s):  
Aluminium Alloy ◽  
Analytical Model ◽  
Impact Loading ◽  
Impact Load ◽  
Yield Criterion ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Proposed Model ◽  
The Impact

This paper proposes a new analytical model to predict plastic deformation and strain distributions in aluminium-alloy plates under low velocity impact loading. The low velocity impact load on the fully clamped circular plate was idealized as a quasi-static normal point force acting at the centre of plate. Based on apt geometrical approximation and assumptions, governing equations were established to predict the out-of-plane deflection and the radial tensile, radial and circumferential flexure strains in fully clamped conditions. From the deformation theory of plasticity, a new formula was derived to estimate the impact load by incorporating strain-energy approach, bilinear strain-hardening constitutive model and the one-dimensional Tresca yield criterion. Low velocity impact tests were performed to confirm the proposed model and good correlation was achieved between the predictions and actual experiments, demonstrating the practical and effective use of the proposed model.

Comparative Study of Fiber Metal Laminates (FMLs) and Aluminum Skins for Polypropylene (PP) Honeycomb Core Sandwich Structure under Low Velocity Impact Loads

2011 ◽  
Vol 471-472 ◽  
pp. 524-529
Author(s):  
Md Akil Hazizan ◽  
C.Y. Tan
Keyword(s):  
High Speed ◽  
Sandwich Structure ◽  
Pure Aluminum ◽  
Low Velocity Impact ◽  
Honeycomb Core ◽  
Low Velocity ◽  
Time Histories ◽  
Force Time ◽  
Impact Energies ◽  
The Impact

In this study, the impact responses of sandwich structure with both FML and aluminum skins were compared. The force-time histories from the low-velocity drop weight impact tester were recorded under various impact energies. Energy absorbed from the two types of sandwich structures under various impact energies were also calculated by measuring its initial velocity before impact from a series of recorded high speed camera pictures and force-time histories. Based on results obtained, pure aluminum skins with PP honeycomb core that being impacted by lower impact energies shows higher absorbed energies as compared to FML skins. However with higher impact energies the FML skins shows improvement over the aluminum with higher energy absorption capacity. Damages created were also being characterized under optical microscope for further investigation.

Investigation on Shock Response of Magnesium Alloy Honeycomb Sandwich Panels under Low Velocity Impact Loading

2011 ◽  
Vol 675-677 ◽  
pp. 547-550
Author(s):  
Hong Yang Zhao ◽  
Dong Ying Ju ◽  
Yasumi Ito ◽  
Tetsuya Nemoto ◽  
Yoshie Takahashi
Keyword(s):  
Magnesium Alloy ◽  
High Speed ◽  
Sandwich Panels ◽  
Low Velocity Impact ◽  
Dynamic Force ◽  
Low Velocity ◽  
Velocity Impact ◽  
Honeycomb Sandwich ◽  
Shock Response ◽  
The Impact

This paper describes the results of an experimental investigation on the drop off impact test on a range of sandwich panels. The magnesium alloy sandwich panels were fabricated with rolled sheets at different thickness by pressing and bonding method. Out-plane compression test was employed to obtain its basic deformation-force behavior. The impact experiments were carried out in which a steel cylinder was dropped off at various height levels, ranging from 0.5m to 1.5 cm to impact the panel. A high speed camera was employed to take pictures at 20 thousand frames per second and the low-velocity impact response on the sandwich panels is recorded with a dynamic force senor under the panel simultaneously. The shock response with time and the impact absorption energy were analyzed and compared. The results of this study proved that the magnesium alloy honeycomb sandwich panels have good impact energy absorption performance.

SIMPLIFIED ANALYSIS OF LOW VELOCITY IMPACT ACTIONS ON SHALLOW DOMES

2013 ◽  
Vol 05 (02) ◽  
pp. 1350013 ◽  
Author(s):  
YI YANG ◽  
NELSON LAM ◽  
LIHAI ZHANG ◽  
EMAD GAD
Keyword(s):  
Nonlinear Behavior ◽  
Low Velocity Impact ◽  
Elastic Behavior ◽  
Response Behavior ◽  
Lumped Mass ◽  
Low Velocity ◽  
Mass Model ◽  
Simplified Approach ◽  
Lumped Masses ◽  
The Impact

This paper is concerned with a simplified approach of estimating the effects of the impact of a projectile on a circular dome. The procedure to be introduced involves simplifying the impactor (projectile) and the target (the dome) by a two-degree-of-freedom (2DOF) system which is made up of two lumped masses connected by elastic springs. This modeling approach has only been adapted for analyzing the impact response behavior of beams and plates. The original contributions of this paper is the development of equations and charts for estimating the value of the lumped mass and spring stiffness in the 2DOF lumped mass model to emulate the response behavior of circular domes. Linear elastic behavior of the dome is assumed but nonlinear behavior of the impactor has been taken into account. The developed calculation procedure has been validated and illustrated by case studies.

Numerical Modeling on Low Velocity Impact on a Foam Core Sandwich Panel

2014 ◽  
Vol 527 ◽  
pp. 53-56 ◽  
Author(s):  
Zong Hong Xie ◽  
Qun Yan
Keyword(s):  
Sandwich Panel ◽  
Failure Modes ◽  
Time History ◽  
Matrix Cracking ◽  
Low Velocity Impact ◽  
Foam Core ◽  
Cohesive Elements ◽  
Low Velocity ◽  
Stress Criterion ◽  
The Impact

This paper introduces a kinetic model to simulate a foam-core composite sandwich panel impacted by a solid semi-sphere. A modified Hashin failure criterion, which consider failure modes of fiber breakage, matrix cracking and matrix crushing, are implemented into the model analysis by using a self-developed VUMAT subroutine. Cohesive elements with zero-thickness are used in the composite laminates model and quadratic nominal stress criterion is used to predict the delamination initiation during the impact. A crushable foam model is used for foam core. The time history curve of contact force is obtained and shows a good correlation with the experimental data.

Experimental and analytical model for the penetration and indentation prediction on BFRP laminates under low velocity impacts

2020 ◽  
pp. 002199832096979
Author(s):  
I Papa ◽  
A El Hassanin ◽  
T Langella ◽  
V Lopresto
Keyword(s):  
Analytical Model ◽  
Impact Energy ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Basalt Fibre ◽  
Reinforced Plastics ◽  
Reinforced Plastic ◽  
Laminate Thickness ◽  
The Impact ◽  
Plastic Laminates

Low velocity impact tests at different impact energies were performed on basalt fibre reinforced plastic laminates, varying laminate thickness, stacking sequence, support dimensions and indenter diameter. A previous modified analytical model for the prediction of the indentation as a function of the impact energy, valid for carbon and glass fibre reinforced plastic laminates, was applied: a different behaviour was observed denoting an other damage mechanisms of the basalt fibre laminates. About the prediction of the penetration energy, the previous model largely applied in the literature showing the importance of the total fibre content was adopted, and a good agreement between the theoretical predictions and the experimental results was found. In analysing previous experimental data, in comparison to those of carbon fibre reinforced plastics, higher impact energy was found to be necessary to penetrate the basalt laminates whereas the indentation depth at the same impact energy was lower. A larger number of tests were carried out to validate a preliminary work done by the authors.

On the low- and high-velocity impact behaviour of hybrid composite materials at room and extreme temperature

2021 ◽  
pp. 002199832110476
Author(s):  
Ilaria Papa ◽  
Federica Donadio ◽  
Vicente Sánchez Gálvez ◽  
Valentina Lopresto
Keyword(s):  
Hybrid Composite ◽  
High Velocity ◽  
Composite Laminates ◽  
Composite Structures ◽  
High Speed ◽  
Extreme Temperature ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact

A demand raised is how to improve the survivability of aircraft and naval structures concerning low- and high-velocity impacts. Since fundamental failure is due to mainly by fracture, a fundamental understanding of both mechanisms and mechanics of the material is crucial. It is important to understand the deformation and damage mechanisms involved in the impact to improve the design of composite structures. Several approaches have been exploited to improve the impact damage resistance of composite laminates in different conditions. Among these, the development of composite laminates stacking different fibres in the same matrix results very interestingly. This paper deals to investigate on the high and low speed impact performance of hybrid composite configurations made of glass/carbon and basalt fibres. Low-velocity impact at penetration and high speed tests at different impact velocity were carried out at the room and low temperatures to evaluate the goodness of hybridization proposed and the temperature effect on the composite performances. Among the three proposals, a hybrid basalt carbon configuration was identified as the best both at low speeds and at high impact speeds for both temperatures tested.

SIMULATIONS OF RESPONSE TO LOW VELOCITY IMPACT BY SPREADSHEET

2010 ◽  
Vol 10 (03) ◽  
pp. 483-499 ◽  
Author(s):  
N. T. K. LAM ◽  
H. H. TSANG ◽  
E. F. GAD
Keyword(s):  
Approximate Solutions ◽  
Low Velocity Impact ◽  
Elastic Response ◽  
Governing Equations ◽  
Lumped Mass ◽  
Low Velocity ◽  
Computational Tools ◽  
Single Degree Of Freedom ◽  
Dynamic Analyses ◽  
The Impact

A program which can be used to simulate the elastic response of lumped mass single-degree-of-freedom systems to impact actions is introduced in this paper. The underlying governing equations and the implementation of their solutions on a spreadsheet are described. As illustrated in the paper, the program can be extended to obtaining approximate solutions for the inelastic response of a reinforced column to the impact by a vehicle. Solutions obtained from the developed spreadsheet have been compared with those obtained by other means. Few engineers have the skills of undertaking their own sanity checks on analyses involving transient actions including that of the impact of an object. Codes of practices often resort to the use of equivalent static loading for representing transient actions and this may give misleading results. Portable and inexpensive computational tools like the ones presented herein enable engineers to conveniently undertake their own sanity checks on computer output from dynamic analyses.

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