Hypervelocity Impact Damage Research Articles

Design of multi-objective guided filter infrared thermal image fusion for hypervelocity impact damages detection

Spacecraft hypervelocity impact damage assessment is becoming increasingly important as the space debris environment deteriorates. Common single-target guided filtering methods are hardly capable of coping with the complex damage infrared thermal image fusion requirements of hypervelocity impacts. In this paper, a two-layer infrared reconstructed image fusion algorithm based on Multi-objective guided filtering (MOGF) is proposed. The aim is to keep the filtered input and output images similar while reducing thermal image noise and retaining as much of the tiny defects as possible in the fusion process. MOGF combines a multi-objective evolutionary optimization algorithm to simultaneously optimize multiple guided filter cost functions in the form of vectors in order to obtain the optimal set of guided filter weight parameters. Given the problem of irregular frontier surfaces in practical multi-objective optimization problems, a weight vector adaptive adjustment strategy is introduced to obtain a more uniform population. Finally, the optimal weight set is passed to the full pixel fusion layer to complete the complex damage infrared reconstructed image fusion. The experiments demonstrate that the proposed fusion method considering multiple targets has higher performance in hypervelocity impact complex damage fusion compared to the general single target fusion method.

Analysis of hypervelocity-impacted thin films for space applications

Exposure to the harsh space environment and hypervelocity impacts from micrometeoroids and small orbital debris can affect space operations through long-term degradation of spacecraft materials, surfaces, or systems. Multi-layer insulation (MLI) and coated polyimide films are spacecraft materials commonly found on the external surfaces of spacecraft for thermal control and protection. Characterizing the damage to these exposed materials with in situ and laboratory measurements can better inform spacecraft designers and operators in understanding and mitigating surface or system degradation. In this paper, we examine flown Hubble Space Telescope (HST) Equipment Bay 5 MLI and coated polyimide hypervelocity ground tested articles to characterize hypervelocity impact damage. Impact feature cavities are inspected to identify damage, which can validate long-term degradation models, improve thermal management systems, or improve accuracy of damage predictions. An overview of the impact characterization using optical microscopy, narrow-band spectroscopy, and Scanning Election Microscopy/Energy Dispersive X-ray (SEM/EDX) of the two materials is presented. Observations of robustness in the space environment, as well as a detailed assessment of cratering and penetration statistics for the space-exposed sample, are also discussed.

Experimental and numerical study of hypervelocity impact damage on composite overwrapped pressure vessels

Ground-based tests are important for studying hypervelocity impact (HVI) damage to spacecraft pressure vessels in the orbital debris environment. We analyzed the damage to composite overwrapped pressure vessels (COPVs) in the HVI tests and classified the damage into non-catastrophic damage and catastrophic damage. We proposed a numerical simulation method to further study non-catastrophic damage and revealed the characteristics and mechanisms of non-catastrophic damage affected by impact conditions and internal pressures. The fragments of the catastrophically damaged COPVs were collected after the tests. The crack distribution and propagation process of the catastrophic ruptures of the COPVs were analyzed. Our findings contribute to understanding the damage characteristics and mechanisms of COPVs by HVIs.

Numerical analysis of oblique hypervelocity impact damage to space structural materials by ice particles in cryogenic environment

A phase-aware constitutive model is developed and integrated with the meshfree simulations to study the failure mechanisms of space structural materials under the oblique hypervelocity impact of ice. The proposed constitutive model covers material’s dynamic behavior in a wide range of temperature, pressure, and strain rates. The numerical analysis combines the Hot Optimal Transportation Meshfree method with the EigenErosion algorithm to explicitly account for large deformation, brittle and ductile failure, phase transition, and debris cloud formation in the target materials and ice projectile. Specifically, the surface erosion and crater formation in the target under different impact speeds and angles are characterized by the damage’s shapes, depth, and length. The predicted crater depths in the Al6061 targets are validated by the Cour-Palais empirical model. It is evident that the damage to the space structural material by ice particles results from the competition between fracture, plasticity, and phase transition in the materials. The impact angle and velocity determine the crater deformation and the potential thread of the ejected debris.

Infrared feature extraction and prediction method based on dynamic multi-objective optimization for space debris impact damages inspection

This paper develops a damage-risk assessing method with dynamic feature extraction optimization (DFEO) in the Thermal-wave image technique, to evaluate the hypervelocity impact (HVI) damages in dynamic meteoroid/orbital debris (M/OD) environment rapidly. The proposed DFEO not only investigates how to select effectively each representative temperature point (RTP) with consideration of similarities and differences of thermal characteristic data, but also studies how to utilize historical information to extract rapidly impact damage feature from thermal image sequence. A multi-directional prediction method (MPM) in DFEO calculates the degree of environment change to depict the configuration of previous Pareto set (PS) and predict the moving directions of the optimal solutions. Meanwhile, a dynamic multi-objective particle-swarm optimization strategy (DM-PSOS) in DFEO guarantees that the obtained initial population evolves successfully to Pareto Front (PF). Besides DFEO, the assessing method contains variable step-size search, clustering analysis and damage visualization, to enhance the detection efficiency. The experimental study on HVI damage detection demonstrates the capabilities of the proposed method.

Using an Optimal Multi-Target Image Segmentation Based Feature Extraction Method to Detect Hypervelocity Impact Damage for Spacecraft

Aerospace has become an indispensable part of exploring the universe. To guarantee the safety of the materials on aerospace, the recognition and the detection of hypervelocity impact (HVI) damage is needed. Processing bottlenecks and the lack of precision acquisition tools have restricted detection to the HVI damage of space debris for on-orbit spacecraft. This paper proposes an optimal multi-target image segmentation based feature extraction method to detect the HVI damage. For the collected infrared data, an improved mean shift clustering algorithm is given to adaptively classify the temperature change characteristics in the sampled data of the infrared video stream and reconstruct the image to obtain the infrared reconstruction image reflecting the damage characteristics. Moreover, a multi-objective optimization segmentation model is proposed to segment the defects of infrared reconstructed images to further extract the geometric shape, depth and other features of various defects. To obtain accurate segmentation results of the infrared reconstructed thermal images, the segmentation objective functions are set with respect to noise elimination and detail reservation. A weight vectors adjustment algorithm is developed to further improve the accuracy of damage segmentation in the multi-objective optimization segmentation model, to derive better balance between detail retention and noise removal. The experimental results of the algorithm verify the effectiveness and benefits of the proposed method.

Experimental and analytical assessment of the hypervelocity impact damage of GLAss fiber REinforced aluminum

This article addresses the response of GLAss fiber REinforced aluminum to hypervelocity impacts of micrometeoroid analogs at impact velocities of 7 km/s and beyond. In relation, the damage modes of different GLAss fiber REinforced aluminum configurations have been exemplified. The GLAss fiber REinforced aluminum configurations comprised six to twelve variably thick aluminum layers and up to four plies of glass fiber reinforced epoxy per composite laminate. Hypervelocity impact experiments have been conducted with the help of a two-stage light-gas gun, wherein aluminum- and stainless steel projectiles were launched at velocities up to 7.15 km/s. Visual inspection of the damage area suggested the dissipation of impact energy in elastic-plastic deformation, petalling, delamination, debonding, tensile failure of fibers, and pyrolysis of epoxy. A prevailing damage mode was not apparent albeit. The quasi-isotropic ply orientation of S2-glass/FM94-epoxy laminates promoted the interference of shock- and rarefaction waves and suppressed the damage area of GLAss fiber REinforced aluminum. To discriminate between the impact performance of different GLAss fiber REinforced aluminum configurations, the energy dissipated in different damage modes of GLAss fiber REinforced aluminum has been assessed quantitatively. In terms of normalized energy, the cross-ply GLAss fiber REinforced aluminum dissipated higher energy in petal formation than in other primary damage modes. The normalized petalling energy was found to decline with the increase of impact energy. The outcomes of this study will help to optimize the GLAss fiber REinforced aluminum laminate, which will be employed as a bumper shield to prevent the fatal damage and the unzipping of a spacecraft pressure bulkhead.

Experimental investigation on the hypervelocity impact damage behavior of polyimide film

The damage behaviors of polyimide film hypervelocity impacted by the aluminum micro–flyer, accelerated by a laser driven flyer (LDF) system, are studied. The fracture morphologies of the impacted films are observed and measured by scanning electron microscopy (SEM). Aided with the technique of LDF and SEM, a parametric study on the HVI responses of polyimide film is implemented and the influence factors, including the film thickness, impact velocity, pre–stress level and flyer shape, are discussed. Results show that the damage behaviors of polyimide film are governed by the synergistic effect of the temperature and strain rate, and a three–zone fracture mechanism is proposed to explain the fracture phenomena. Furthermore, according to the experimental results, a series of damage parameters are defined to characterize the film's damage morphology, and then a comprehensive damage evaluation model is presented. Based on this model, a quantifiable damage grade system is established, in which the damage extent of the impacted film can be assessed under the different conditions.

A Novel Method for Damage Prediction of Stuffed Protective Structure Under Hypervelocity Impact by Stacking Multiple Models

Adopting appropriate protective structures to resist the impact of micrometeoroid or space debris on spacecraft is a valuable research content of space engineering. After the single-layer board and Whipple protective structure, the stuffed protective structure has become one of the research focuses in recent years. However, due to the different filling materials and filling modes, the prediction of hypervelocity impact damage of projectile by using the explicit ballistic limit equation of the stuffed protective structure will lead to some deviation between the predicted results and the measured data. In this paper, the problem is transformed into a binary classification problem, which is characterized by projectile impact parameters and protective structure parameters. And a novel method is proposed to predict the hypervelocity impact damage of the stuffed protective structure under the stacking ensemble learning framework. In this method, the hypervelocity impact damage data set of the stuffed protective structure is firstly divided into specific data subsets. Extreme Gradient Boosting (XGBoost), Random Forest (RF), Support Vector Machine (SVM), and K-Nearest Neighbor (KNN) are taken as the base models of the stacking ensemble learning framework. And each base model is trained by using the divided sub-datasets. Thus the meta-features with stronger generalization ability are extracted. Then, the Long Short Term Memory (LSTM) network is used as the meta-model of the stacking ensemble learning framework, and the meta-features extracted before are used to train it. In this way, the high-precision prediction of the impact damage of the stuffed protective structure is realized under the small data set. The experimental results show that the stacking ensemble learning model has a good prediction effect on the impact damage of the stuffed protective structure. The cross-validation under different training sample sizes further proves that the stacking ensemble learning model has excellent robustness and accuracy.

Hypervelocity impact damage behavior of B4C/Al composite for MMOD shielding application

In order to improve the survivability of in-orbit spacecraft against the hypervelocity impact (HVI) of space debris, the lightweight B4C/Al composite is fabricated by the pressureless presintering and Al infiltration in vacuum and applied as the bumper of Whipple shield configuration. The HVI tests ranging from 3 km/s to 6.5 km/s are carried out to assess the shield performance of B4C/Al bumper. The fitting line of the ballistic limit for the B4C/Al bumper is obtained, and its critical projectile size can be improved by about 20% in comparison to the conventional Al alloy Whipple shield configuration. Based on the damage features of bumper and rear wall, the B4C ceramic phase of B4C/Al composite is the key reason to break the projectile into smaller fragments or liquid droplets of debris cloud. The Al plastic phase with three-dimensional network enhances the toughness of B4C/Al composite bumper, which plays an important role in avoiding structural failure caused by shock waves. Hence, the impact kinetic energy of debris cloud is obviously dispersed, and the subsequent impact damages on real wall are alleviated accordingly. The primary investigation provided theoretical and technical instructions for the design and application of B4C/Al composite in MMOD shield configuration.

Hypervelocity impact damage prediction of stuffed Whipple shield based on Adaboost

Hypervelocity impact damage prediction of stuffed Whipple shield based on Adaboost

Research on Damages Evaluation Method With Multi-Objective Feature Extraction Optimization Scheme for M/OD Impact Risk Assessment

As the number of space debris (also called meteoroid/orbital debris-M/OD) increases in recent years, the hypervelocity-impact (HVI) events of M/OD on spacecrafts have become one of the most main risks threatening human activity in space. For the automatical M/OD risk assessment, some effective nondestructive testing (NDT) methods are critical to realizing the evaluation of the HVI damages. In this paper, a novel HVI damage evaluation method based on the active infrared thermal wave image detection technology with multi-objective feature extraction optimization (MO-FEO) is proposed to achieve the quantitative evaluation of M/OD HVI damages. For the precise selection of representative temperature point in thermal infrared image data, the proposed MO-FEO method has the advantage not only of considering the difference among temperature points in different thermal temperature categories but also considering the correlation among temperature points of each thermal temperature category. The multi-objective feature extraction problem decomposed by Tchebycheff aggregation is used to seek the representative temperature points through an evolution process brought the selection pressure and fitness value. In addition to the MO-FEO frame, the variable step search and classification of temperature points are also implemented in the HVI damage evaluation strategy to improve efficiency. Some experimental results of infrared detection for the real M/OD HVI test articles are proposed to illustrate the effectiveness of the proposed method.

Hypervelocity impact damage properties of solar arrays by using two-stage light gas gun

Using two-stage light gas gun, we study the hypervelocity impact characteristics of spacecraft key component, solar cell arrays. The damage morphologies in the ground simulation tests match well with those on-situ orbital impacts. The main characteristics of mechanical damage, including the central pit, cover glass shatter zone, and conchiodal spallation, are measured by using a microscope under 20 times magnification. To study the mechanical damage properties in solar arrays, we carry out 15 shots totally, under different impact locations, impact velocities, and particle diameters. Under the condition of impact angel of zero degree, the damage equation of perforation diameter of solar arrays and the damage equation of the diameter of shatter zone in cover glass are developed, respectively. The results show that the perforation diameter and the diameter of cover glass shatter zone are mainly related to the diameter of particle with 2/3 power, while related to the velocity of impact with 1/6 power. Compared with the damage equation in the literature, the damage equations in this article are very suitable for describing hypervelocity impact damage properties of solar arrays used in our country's spacecraft. The results are of significance for our country's aerospace engineering.

Introducing manufacturing features into numerical modeling of hypervelocity impact damage of composite pressure vessels

Composite pressure vessels are extensively used in unmanned spacecraft systems due to high specific strength of composites, which provides higher mass savings as compared to metallic vessels. The most common example is their use as liquid propellant tanks. Being a part of spacecraft, composite vessels are exposed to space environment, and therefore, may be subjected to hypervelocity impacts (HVI) by orbital debris or micrometeoroids. This paper analyzes the manufacturing features such as filament winding pattern and defects of fabrication that may influence the response of composite pressure vessels to HVI, and discusses the ways to introduce those features into the numerical modeling.

Experimental and numerical study of hypervelocity impact damage in composite materials fabricated by filament winding

This paper investigates the behavior of composite materials fabricated by filament winding when subjected to hypervelocity impacts (HVI) by orbital debris. Experimental data revealed that damage induced by orbital debris impacts in filament-wound composites depends on the following parameters: impactor energy, pre-loading, and the degree of interweaving of filament bands. This paper also introduces a meso-scale simulation approach suitable for numerical modeling of the studied phenomena. Findings of the study may be useful for the design of spacecraft components fabricated by filament winding, for example, composite overwrapped pressure vessels (COPVs) and composite truss tubes.

Hypervelocity impact damage and microstructure evolution of woven Ti6Al4V fabric reinforced aluminum matrix composites

For improving the strength and the ductility, woven Ti6Al4V fabric were chosen as the reinforcements for aluminum matrix composites (AMCs). The composites were fabricated by squeeze casting method with a very short solidification time. Interfacial characteristics and hypervelocity impact damage of (2D-Tif)/Al composites were analyzed by means of TEM and HREM. The effects of hypervelocity impact on microstructure evolution in the crater were also discussed. TEM observation showed that TiAl3 interfacial reaction products and TiAl diffusion layer were formed on Ti-Al interfaces during the fabrication stage. Hypervelocity impact results showed that the addition of woven Ti6Al4V fabric improved the hypervelocity impact resistance of aluminum alloy. After hypervelocity impact, the dislocation density in the matrix increased obviously. Microstructure evolution of TiAl diffusion layer was characterized as a phase transition band including TiAl amorphous, nano-grain and multigrain. It was attributed to adiabatic shear temperature rising which caused the formation of amorphous and nano-grain.

Meso-scale modeling of hypervelocity impact damage in composite laminates

ObjectivesThis paper presents an approach to numerical modeling of hypervelocity impact on carbon fiber reinforced plastics (CFRP). MethodsThe approach is based on the detailed meso-scale representation of a composite laminate. Material models suitable for explicit modeling of laminate structure, including fiber-reinforced layers and resin-rich regions, are described. Two numerical impact tests with significantly different impact energies were conducted on thermoplastic AS4/PEEK materials with quasi-isotropic layups. Simulations employed both SPH and Finite element methods. ResultsResults of simulations are verified against experimental data available from the literature and demonstrate good correlation with the experiments. ConclusionsDeveloped modeling approach can be used in simulations where post-impact damage progression in composite material is of the main focus.

Spacecraft damage assessment due to hypervelocity impacts using a micrometeoroid and orbital debris detection system

This paper describes the design, construction, and testing of a hypervelocity impact (HVI) detection system for monitoring the occurrence of an impact, the location of the impact, and the resulting damage to a spacecraft. One of the constant dangers emanating from the space environment is the presence of micrometeoroids and space debris. The energy associated with these hypervelocity impacts is sufficient to penetrate most spacecraft structures, damage spacecraft components, and pose a potential threat to human occupants. A detection system has been developed involving optical fibers woven in an orthogonal grid in a fabric such as Kevlar. The optical fibers are interrogated by a light source that monitors the intensity of the light transmission. Changes in light transmission relate to HVI damage to the optical fibers such that a damage zone can be constructed based on these data. This “smart fabric” can be bonded to critical parts of the spacecraft susceptible to HVI damage or mounted inside the spacecraft structure such that the HVI particles are attenuated before they can damage interior components (and astronauts). Tests on a Kevlar smart fabric have been conducted at the National Aeronautics and Space Administration (NASA) Johnson Space Center using aluminum plate targets, and results are presented demonstrating the effectiveness of this technique.

Hypervelocity impact damage to Ti–6Al–4V meshes reinforced Al–6Mg alloy matrix composites

An Al–6Mg alloy matrix composite reinforced with Ti–6Al–4V meshes was fabricated by pressure infiltration method; its damage behaviors impacted by hypervelocity aluminum projectiles were investigated. Results showed that the thin Ti f/Al–6Mg composite target exhibits better protection efficiency and energy absorption ability than Al–6Mg alloy target. With projectile sizes increasing, bulge and spallation were observed on the back of the composite target. The Ti–6Al–4V meshes were tensed and deformed drastically in the spallation region, where micro-damages such as interfacial debonding and cracks were dominant. Shear localization was the primary failure characteristic for thin Al–6Mg alloy target. The adiabatic shear bands were observed near the crater of Al–6Mg alloy, not in Ti f/Al–6Mg composite target. It was ascribed to the Ti–Al interfacial bonding strength and the high temperature strength for Ti–6Al–4V alloy.

Hypervelocity impact on CFRP: Testing, material modelling, and numerical simulation

Abstract This paper describes the derivation and validation of a numerical material model that predicts the highly dynamic behaviour of CFRP (carbon fibre reinforced plastic) under hypervelocity impact. CFRP is widely used in satellites as face sheet material in CFRP-Al/HC sandwich structures (HC = honeycomb) that can be exposed to space debris. A review of CFRP-Al/HC structures typically used in space was performed. Based on this review, a representative structure in terms of materials and geometry was selected for study in the work described here. An experimental procedure for the characterisation of composite materials is documented by Riedel et al. [ADAMMO – advanced material damage models for numerical simulation codes. ESA CR(P) 4397, EMI report I 75/03, Freiburg; October 31, 2003.]. The test results from the CFRP of the current study allow for the derivation of an experimentally based orthotropic continuum material model data set that is capable of predicting the mechanical behaviour of CFRP under hypervelocity impact. Such a data set was not previously available. In the work by Riedel et al. [Hypervelocity impact damage prediction in composites: part II – experimental investigations and simulations. International Journal of Impact Engineering, 2006;33:670–80.] an orthotropic material data set was used for modelling HVI on AFRP (aramid fibre reinforced plastic), which shows relatively high deformability before failure. The enhancements of the modelling approaches in previous studies [Riedel W, Harwick W, White DM, Clegg RA. ADAMMO – advanced material damage models for numerical simulation codes. ESA CR(P) 4397, EMI report I 75/03, Freiburg; October 31, 2003. Hiermaier S, Riedel W, Hayhurst C, Clegg RA, Wentzel C. AMMHIS – advanced material models for hypervelocity impact simulations. Final report, EMI report E 43/98, ESA CR(P) 4305, Freiburg; July 30, 1999.] necessary to model brittle CFRP are specified. An experimental hypervelocity impact campaign was performed at two different two-stage light gas guns which encompassed both normal and oblique impacts for a range of impact velocities and projectile diameters. Validation of the numerical model is provided through comparison with the experimental results. For that purpose measurements of the visible damage of the face sheets and of the HC core are conducted. In addition, the numerically predicted damage within the CFRP is compared to the delamination areas found in ultrasonic scans.