Numerical Study on Impact Response of Aircraft Sandwich Wing Made of Fiber-Metal Laminate Face-Sheets Subjected to Bird Strike

2012 ◽  
Vol 488-489 ◽  
pp. 8-13 ◽  
Author(s):  
S.M.R. Khalili ◽  
M. Assar ◽  
R. Eslami Farsani ◽  
I. Hajiyousefi
Keyword(s):  
Energy Absorption ◽  
Numerical Study ◽  
Metal Layer ◽  
Element Model ◽  
Fiber Types ◽  
Bird Strike ◽  
Impact Phenomena ◽  
Impact Responses ◽  
Fiber Metal ◽  
The Impact

Aircraft structures are frequently subjected to impacts from objects such as runway debris and birds. In new aircraft structural design, Fiber Metal Laminates (FMLs) play a significant role due to their excellent mechanical properties, particularly the impact properties. In this study, the aircraft sandwich wing with FML face-sheets are analyzed by finite element model for simulating the bird strike. The numerical simulations of bird strike impact are performed adopting a lagrangian approach to design the wing by MSC/PATRAN FE code. The numerical obtained results are compared with the results in the literature for validation of the model. The effect of fiber orientations, fiber types, metal types in FML face sheets in sandwich wing on impact responses are investigated. The impact responses are illustrated by displacement history, contact force history and energy absorption. According to these results, the sandwich panel with FML skin is suitable structure for energy absorption (that is the most important factor in impact phenomena). The lay-ups with titanium metal layer with aramid fibers are the best.

scholarly journals Numerical Study Of The Targeted Energy Transfer Between The Euler-Bernoulli Beam And A Nonlinear Energy Sink

2021 ◽  
Author(s):  
Mohi U. Rahamat Ullah
Keyword(s):  
Energy Transfer ◽  
Primary Structure ◽  
Numerical Study ◽  
Element Model ◽  
Impact Excitation ◽  
Nonlinear Stiffness ◽  
Targeted Energy Transfer ◽  
Stiffness Property ◽  
Energy Sink ◽  
The Impact

Targeted energy transfer (TET) refers to the spatial transfer of energy between a primary structure of interest and isolated oscillators called the energy sink (ES). In this work, the primary structure of interest is a slender beam modeled by the Euler-Bernoulli theory, and the ES is a single-degree-of-freedom oscillator with either linear or cubic nonlinear stiffness property. The objective of this study is to characterize the TET and the effectiveness of ES under impact and periodic excitations. By using the scientific computation package, MATLAB, numerical simulations are carried out based on excitations of various strength and locations. Both time and frequency domain characterizations are used. For the impact excitation, the ES with the cubic nonlinear stiffness property is more superior to the linear oscillator in that larger percentage of the impact energy can be dissipated there. The main energy transfer was found to be due to a 3- to-1 frequency coupling between the first bending mode and the ES. For the periodic excitation, however, both linear and nonlinear ES exhibit generally poorer performance than the case with the impact excitation. Future works should focus on the frequency-energy relationship of the periodic solution of the underlying Hamiltonian, as well as using finite element model to verify the simulation results.

Numerical and Experimental Investigation on the Energy Absorption Capability of a Full-Scale Composite Fuselage Section

2019 ◽  
Vol 827 ◽  
pp. 19-24 ◽  
Author(s):  
Donato Perfetto ◽  
Giuseppe Lamanna ◽  
M. Manzo ◽  
A. Chiariello ◽  
F. di Caprio ◽  
...  
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Load Condition ◽  
Element Model ◽  
Full Scale ◽  
Research Centre ◽  
Fe Method ◽  
Explicit Finite Element ◽  
Crashworthiness Design ◽  
The Impact

In the case of catastrophic events, such as an emergency landing, the fuselage structure is demanded to absorb most of the impact energy preserving, at the same time, a survivable space for the passengers. Moreover, the increasing trend of using composites in the aerospace field is pushing the investigation on the passive safety capabilities of such structures in order to get compliance with regulations and crashworthiness requirements. This paper deals with the development of a numerical model, based on the explicit finite element (FE) method, aimed to investigate the energy absorption capability of a full-scale 95% composite made fuselage section of a civil aircraft. A vertical drop test, performed at the Italian Aerospace Research Centre (CIRA), carried out from a height of 14 feet so to achieve a ground contact velocity of 30 feet/s in according to the FAR/CS 25, has been used to assess the prediction capabilities of the developed FE method, allowing verifying the response under dynamic load condition and the energy absorption capabilities of the designed structure. An established finite element model could be used to define the reliable crashworthiness design strategy to improve the survival chance of the passengers in events such as the investigated one.

A numerical study of the influence of Z-pin parameters on the elastic properties of laminates

2020 ◽  
pp. 096739112097008
Author(s):  
Mengjia Li ◽  
Puhui Chen
Keyword(s):  
Elastic Properties ◽  
Composite Laminates ◽  
Numerical Study ◽  
Element Model ◽  
Fe Model ◽  
Insertion Angle ◽  
Benchmark Tests ◽  
Parametric Analyses ◽  
Longitudinal Modulus ◽  
The Impact

A finite element model with periodic boundary conditions was developed to investigate the influence of different Z-pin parameters including diameter, spacing, and insertion angle of Z-pin on the elastic properties of composite laminates. Benchmark tests were carried out to verify the FE model and a series of parametric analyses were subsequently performed. In general, all the elastic moduli, excluding the through-thickness modulus ( Ez), decreased while Ez increased nonlinearly with increasing Z-pin diameter and decreasing spacing. The reduction of Ey (transverse modulus) was approximately 40% of that of Ex (longitudinal modulus), while the reduction of Gxy is similar to that of Ex. Besides, Gxz and Gyz were reduced by approximately half of the reduction of Gxy. Although the impact of insertion angle was obvious on Ez, it was negligible on the other five moduli.

scholarly journals Numerical Study on the Effect of Z-Warps on the Ballistic Responses of Para-Aramid 3D Angle-Interlock Fabrics

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 479
Author(s):  
Yingxue Yang ◽  
Xiuqin Zhang ◽  
Xiaogang Chen ◽  
Shengnan Min
Keyword(s):  
Energy Absorption ◽  
Numerical Study ◽  
Three Dimensional ◽  
Local Stress ◽  
Woven Fabrics ◽  
Layer By Layer ◽  
Future Design ◽  
Structural Support ◽  
Fabric Structures ◽  
The Impact

In order to achieve an efficient ballistic protection at a low weight, it is necessary to deeply explore the energy absorption mechanisms of ballistic fabric structures. In this paper, finite element (FE) yarn-level models of the designed three-dimensional (3D) angle-interlock (AI) woven fabrics and the laminated two-dimensional (2D) plain fabrics are established. The ballistic impact responses of fabric panels with and without the interlocking Z-warp yarns during the projectile penetration are evaluated in terms of their energy absorption, deformation, and stress distribution. The Z-warps in the 3D fabrics bind different layers of wefts together and provide the panel with structural support along through-the-thickness direction. The results show that the specific energy absorption (SEA) of 3D fabrics is up to 88.1% higher than that of the 2D fabrics. The 3D fabrics has a wider range of in-plane stress dispersion, which demonstrates its structural advantages in dispersing impact stress and getting more secondary yarns involved in energy absorption. However, there is a serious local stress concentration in 2D plain woven fabrics near the impact location. The absence of Z-warps between the layers of 2D laminated fabrics leads to a premature layer by layer failure. The findings are indicative for the future design of ballistic amors.

Analyses on the In-Plane Impact Resistance of Auxetic Double Arrowhead Honeycombs

2015 ◽  
Vol 82 (5) ◽  
Author(s):  
Jinxiu Qiao ◽  
Chang Qing Chen
Keyword(s):  
Energy Absorption ◽  
High Velocity ◽  
Theoretical Models ◽  
Absorption Capacity ◽  
Functionally Graded ◽  
High Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Responses ◽  
The Impact

Double arrowhead honeycombs (DAHs) are a type of auxetic materials, i.e., showing negative Poisson's ratio (NPR), and are promising for energy absorption applications. Their in-plane impact responses are theoretically and numerically explored. Theoretical models for the collapse stress under quasi-static, low-velocity, and high-velocity impacts are developed, based upon the corresponding microstructural deformation modes. Obtained results show that the collapse stress under quasi-static and low velocity impacts depends upon the two re-entrant angles responsible for NPR, while it is insensitive to them under high-velocity impact. The developed theoretical models are employed to analyze the energy absorption capacity of DAHs, showing the absorbed energy under high-velocity impact approximately proportional to the second power of velocity. Extension of the high-velocity impact model to functionally graded (FG) DAHs is also discussed. Good agreement between the theoretical and finite element (FE) predictions on the impact responses of DAHs is obtained.

Ballistic performance and damage simulation of fiber metal laminates under high-velocity oblique impact

2020 ◽  
Vol 29 (7) ◽  
pp. 1011-1034 ◽  
Author(s):  
Chao Zhang ◽  
Qian Zhu ◽  
Jose L Curiel-Sosa ◽  
Tinh Quoc Bui
Keyword(s):  
Impact Velocity ◽  
High Velocity ◽  
Damage Mechanics ◽  
Failure Modes ◽  
Element Model ◽  
Oblique Impact ◽  
Ballistic Performance ◽  
Fiber Metal Laminates ◽  
Fiber Metal ◽  
The Impact

Fiber metal laminates have been successfully applied in military aircrafts, armor vehicles and other modern engineering industries as protective structures due to their outstanding impact resistant properties. Prediction of the ballistic performance and investigation on the damage mechanism of the fiber metal laminates under general oblique impact conditions still remain a very challenging issue. In this study, a nonlinear dynamic finite element model in terms of continuum damage mechanics including intra- and inter-layer failure modes is presented. The accuracy of this model is validated with available experimental data. The damage and ballistic performance of two different structural fiber metal laminates subjected to high-velocity oblique impact by rigid hemispherical nose projectile with angles of 0°, 30°, 45° and 60° are studied. The numerical results show that the projectile deflects when the oblique impact occurs and the deflection angle decreases with increasing the impact velocity. The residual velocity of the projectile and the energy absorption of the target are related to the initial impact velocity and impact angle of the projectile. The proposed simulation approach offers a new proper reference for numerical investigations of common oblique impact problems in other fiber metal laminates.

scholarly journals Atmosphere and Ocean Modeling on Grids of Variable Resolution—A 2D Case Study

2014 ◽  
Vol 142 (5) ◽  
pp. 1997-2017 ◽  
Author(s):  
Peter D. Düben ◽  
Peter Korn
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Numerical Study ◽  
Element Model ◽  
Ocean Modeling ◽  
Local Error ◽  
Grid Refinement ◽  
Variable Resolution ◽  
Geostrophic Balance ◽  
The Impact

Abstract Grids of variable resolution are of great interest in atmosphere and ocean modeling as they offer a route to higher local resolution and improved solutions. On the other hand there are changes in grid resolution considered to be problematic because of the errors they create between coarse and fine parts of a grid due to reflection and scattering of waves. On complex multidimensional domains these errors resist theoretical investigation and demand numerical experiments. With a low-order hybrid continuous/discontinuous finite-element model of the inviscid and viscous shallow-water equations a numerical study is carried out that investigates the influence of grid refinement on critical features such as wave propagation, turbulent cascades, and the representation of geostrophic balance. The refinement technique the authors use is static h refinement, where additional grid cells are inserted in regions of interest known a priori. The numerical tests include planar and spherical geometry as well as flows with boundaries and are chosen to address the impact of abrupt changes in resolution or the influence of the shape of the transition zone. For the specific finite-element model under investigation, the simulations suggest that grid refinement does not deteriorate geostrophic balance and turbulent cascades and the shape of mesh transition zones appears to be less important than expected. However, the results show that the static local refinement is able to reduce the local error, but not necessarily the global error and convergence properties with resolution are changed. The relatively simple tests already illustrate that grid refinement has to go along with a simultaneous change of the parameterization schemes.

Agricultural aircraft wing slat tolerance for bird strike

2017 ◽  
Vol 89 (4) ◽  
pp. 590-598 ◽  
Author(s):  
Adam Deskiewicz ◽  
Rafał Perz
Keyword(s):  
Finite Element ◽  
Impact Velocity ◽  
Structural Response ◽  
Element Model ◽  
Bird Strike ◽  
Element Analysis ◽  
Content Type ◽  
Explicit Finite Element ◽  
Explicit Finite Element Analysis ◽  
The Impact

Purpose The aim of this study is to assess and describe possible consequences of a bird strike on a Polish-designed PZL-106 Kruk agricultural aircraft. Due to its susceptibility to such events, a wing slat has been chosen for analysis. Design/methodology/approach Smooth particle hydrodynamics (SPH) formulation has been used for generation of the bird finite element model. The simulations were performed by the LS-Dyna explicit finite element analysis software. Several test cases have been analysed with differing parameters such as impact velocity, initial velocity vector direction, place of impact and bird mass. Findings Results of this study reveal that the structure remains safe after an impact at the velocity of 25 m/s. The influence of bird mass on slat damage is clearly observable when the impact velocity rises to 60 m/s. Another important finding was that in each case where the part did not withstand the applied load, it was the lug where first failure occurred. Some of the analysed cases indicated the possibility a consequent wing box damage. Practical implications This finding provides the manufacturer an important insight into the behaviour of the slat and suggests that more detailed analysis of the current lug design might improve the safety of the structure. Originality/value Even though similar analyses have been performed, they tended to focus on large transport aircraft components. This investigation will enhance our understanding of structural response of small, low-speed aircraft to a bird impact, which is a realistic scenario for the chosen case of an agricultural plane.

An experimental and numerical study of epoxy-based Kevlar-basalt hybrid composites under high velocity impact

2021 ◽  
pp. 152808372199090
Author(s):  
Azizolrahman Amirian ◽  
Hossein Rahmani ◽  
Hossein Moeinkhah
Keyword(s):  
Energy Absorption ◽  
High Velocity ◽  
Hybrid Composites ◽  
Numerical Study ◽  
Energy Levels ◽  
High Velocity Impact ◽  
Residual Velocity ◽  
Velocity Impact ◽  
The Impact ◽  
Ballistic Apparatus

In this paper, the high velocity impact (HVI) behavior of epoxy-based Kevlar-Basalt hybrid composites was studied experimentally and numerically. The composite specimens were manually placed in nine layers classified into six types of stacking sequences: non-hybrid, sandwich hybrid, and intercalated hybrid. The impact tests were conducted by using a ballistic apparatus at three different energy levels: 150 J, 200 J, and 250 J, and the amount of absorbed energy was calculated based on input velocity and residual velocity of the projectile. The results demonstrated that hybridization improves the behavior of composites in high velocity impacts compared to that of specimen that are not hybridized. The absorption of sandwich hybrids on average increased 23.25% and 11.3% compared to pure Basalt and Kevlar, respectively. Moreover, the intercalated hybrids showed an efficiency of about 35.6% and 21.76% better than that of pure Basalt and Kevlar, respectively, in absorbing energy. The same energy absorption pattern was observed in numerical simulation performed in ABAQUS/Explicit. Also, the highest amount of energy absorption and the lowest residual velocity as well as damage occurred when Kevlar was attacked by the projectile and the layers were intercalated.

Sign in / Sign up

Export Citation Format

Share Document