Drop Impact Test Research Articles

Life Cycle Assessment and Experimental Mechanical Investigation of Test Samples for High-Performance Racing Boats

This paper investigates the environmental impact and mechanical performance of two composite sandwich structures, named Series 1 and Series 2, used in high-performance racing boats. Mechanical tests, including four-point bending and drop impact tests, were performed. It was found on a general basis that Series 2 has higher load-bearing capacity and limited deflection. Series 1, which has a higher density, was able to absorb more impact energy but was more susceptible to damage. A Life Cycle Assessment (LCA) was conducted to evaluate the environmental impact associated with the materials, considering also the testing phase, which plays an important role in the life cycle of materials and structures for advanced marine applications. In addition, two performance indexes were introduced to correlate the mechanical and environmental properties of the analyzed materials. This study emphasizes the importance of considering the testing phase in LCA, as the energy-intensive nature of mechanical testing contributes significantly to the overall environmental impact. The introduced indexes allow for a more comprehensive understanding of the balance between mechanical performance and environmental sustainability. The findings suggest a trade-off between mechanical performance and sustainability, calling for further research into recyclable composites and greener manufacturing processes to balance these competing priorities.

Manipulating localized geometric characteristics in multistable energy-absorbing architected materials

Optimizing global geometric features of unit cells and their spatial arrangements have been well studied in multistable energy-absorbing architected materials (MEAMs), yet their optimized geometries could lead to highly complex features that require expensive additive manufacturing techniques. In this study, we introduce a generalized design strategy to adjust localized thickness variation of thin curved beams in MEAMs. We numerically identify the optimal non-uniform modulation parameter for maximizing energy trapping capacity across MEAM cells, arrays, and cylinders. Then, quasi-static compression and drop impact tests on MEAM cylinders with non-uniform designs are conducted to prove the proposed method's effectiveness in achieving equivalent energy-absorbing abilities with the same material consumption. Overall, we believe that our easy-to-implement strategy can be applied to any type of MEAM with slender beam elements and embedded into energy-absorbing devices and structures.

Study on energy absorption of paper honeycomb sandwich tube filled by polyethylene foam under axial loading

This work proposed an approach to multi-component non-metallic materials, namely regular polygonal paper honeycomb sandwich tubes filled with polyethylene (PE) foam, and focused on the influence of drop impact parameters and structural parameters on the deformation characteristics and energy absorption of the filled tubes. Axial drop impact tests were employed to exert drop impact loading on cross-sections of the specimens with a square drop weight. The results showed that the X-direction filled tube (X-DFT) had a higher crushing strength and yield strength than that of the Y-direction filled tube (Y-DFT). As the tubular cross-section edge number of the filled tube increased, the specific energy absorption (SEA) and specific total efficiency (STE) decreased. Under the same axial drop impact loading conditions, the SEA and STE of the X-DFT were superior to those of the Y-DFT. As the edge number of the tubular cross-section or the tubular length ratio increased, the SEA and STE of the filled honeycomb tube decreased significantly. While the impact energy increased, the SEA and STE of the filled tubes increased approximately linearly. This work investigated the influence of drop-impact and structural parameters on deformation characteristics and energy absorption. It is expected to provide supplementary documentation for the advancement of cushion protection technology and the optimization of product structure.

Enhancing durability of superhydrophobic surfaces via nanoparticle-induced bipolar interface effects and micro-nano composite structures: A femtosecond laser and chemical modification approach

Superhydrophobic coatings are vital in energy, aerospace, and chemical engineering, while their complex preparation and limited durability hinder widespread application. Therefore, inspired by the unique structures of hydrophobic cotton surfaces and mosquito eyes in nature, a durable aluminum alloy superhydrophobic surface is developed using a combination of femtosecond laser and chemical modification methods. Initially, porous microneedle micro-nanostructures are ablated on the surface of the aluminum alloy via femtosecond laser technology. Then, epoxy resin modified with γ-aminopropyl triethoxysilane (KH550) forms a covalently bonded intermediate layer. Finally, biphasic silicon dioxide (BP-SiO2) nanoparticles modified by hexadecyltrimethoxysilane (HDTMS) are used to construct the top hydrophobic layer. The covalent interface interactions between the aluminum alloy substrate and the intermediate layer, as well as between the intermediate layer and the top layer, significantly enhance the durability of the superhydrophobic surface. The prepared F-M@KH-EP/BP-SiO2 coating exhibits outstanding superhydrophobic properties, with a water contact angle (CA) as high as 168.56° and a sliding angle (SA) as low as 1.52° More encouragingly, the composite coating maintains its excellent water resistance even when subjected to harsh mechanical durability damage, including sandpaper wear, tape stripping tests, water drop and sand impact tests. Moreover, the prepared coatings maintain distinguished non-wettability in harsh operating conditions such as corrosive liquid environments, ultraviolet radiation, ultrasonic vibration, etc. Additionally, the coating demonstrates remarkable self-cleaning properties. Superhydrophobic surface durability is significantly enhanced by combining nanoparticle-induced bipolar interface effect and micro-nano structures. These findings provide theoretical reference for the design and application of durable superhydrophobic coatings.

Impact Experiment and Buckling Criterion Analysis of Thin-Walled Cylindrical Shells

The impact test of tubular components is usually carried out by way of drop hammer impact. In fact, in many ships’ equipment, the form of load is often carried out by way of drop impact test. In this paper, the drop impact test is used to study the buckling of tubular structure under impact load, so as to make it closer to the impact form of components in actual ship structure. Firstly, the stress, strain, acceleration at each moment and the buckling deformation mode of the tubular member after the impact are obtained through the drop impact experiment, and then the impact process is analyzed. Secondly, the finite element method is used for numerical simulation of the impact process, and the accuracy of the finite element analysis results is verified by comparing with it. Thirdly, the finite element method proved to be effective and was used to simulate single and multiple drop impacts under more working conditions, and a large amount of data was obtained. Finally, according to the existing impact criteria based on the results of drop weight impact, it is applied to the drop impact process, and the accuracy of each impact criterion is analyzed and compared. This method makes up for the deficiency of the traditional experimental method of using falling weight to simulate impact, and provides a reference for the critical buckling condition of similar thin-walled cylindrical shells under impact.

Collision-Damage Analysis of a Floating Offshore Wind Turbine Considering Ship-Collision Risk

As the number of offshore wind-power installations increases, collision accidents with vessels occur more frequently. This study investigates the risk of collision damage with operating vessels that may occur during the operation of an offshore wind turbine. The floater used in the collision study is a 15 MW UMaine VolturnUS-S (semi-submersible type), and the colliding ships are selected as multi-purpose vessels, service operation vessels, or anchor-handling tug ships based on their operational purpose. Collision analysis is performed using ABAQUS and substantiation is performed via a drop impact test. The collision analyses are conducted by varying the ship velocity, displacement, collision angle, and ship shape. By applying this numerical model, the extent of damage and deformation of the collision area is confirmed. The analysis results show that a vessel with a bulbous bow can cause flooding, depending on the collision conditions. For damage caused by collision, various collision angles must be considered based on the internal stiffener arrangement. Additionally, the floater can be flooded with relatively small collision energy when the colliding vessel has a bulbous bow.

Robust and Superhydrophobic Polydimethylsiloxane/Ni@Ti3C2Tx Nanocomposite Coatings with Assembled Eyelash-Like Microstructure Array: A New Approach for Effective Passive Anti-Icing and Active Photothermal Deicing.

To solve the problem of ice condensation and adhesion, it is urgent to develop new anti-icing and deicing technologies. This study presented the development of a highly efficient photothermal-enhanced superhydrophobic PDMS/Ni@Ti3C2Tx composite film (m-NMPA) fabricated cost-effectively and straightforwardly. This film was fabricated utilizing PDMS as a hydrophobic agent, adhesive, and surface protector, while Ni@Ti3C2Tx as a magnetic photothermal filler innovatively. Through a simple spraying method, the filler is guided by a strong magnetic field to self-assemble into an eyelash-like microstructure array. The unique structure not only imparts superhydrophobic properties to the surface but also constructs an efficient "light-capturing" architecture. Remarkably, the m-NMPA film demonstrates outstanding superhydrophobic passive anti-icing and efficient photothermal active deicing performance without the use of fluorinated chemicals. The micro-/nanostructure of the film forms a gas layer, significantly delaying the freezing time of water. Particularly under extreme cold conditions (-30 °C), the freezing time is extended by a factor of 7.3 compared to the bare substrate. Furthermore, under sunlight exposure, surface droplets do not freeze. The excellent photothermal performance is attributed to the firm anchoring of nickel particles on the MXene surface, facilitating effective "point-to-face" photothermal synergy. The eyelash-like microarray structure enhances light-capturing capability, resulting in a high light absorption rate of 98%. Furthermore, the microstructure aids in maintaining heat at the uppermost layer of the surface, maximizing the utilization of thermal energy for ice melting and frost thawing. Under solar irradiation, the m-NMPA film can rapidly melt approximately a 4 mm thick ice layer within 558 s and expel the melted water promptly, reducing the risk of secondary icing. Additionally, the ice adhesion force on the surface of the m-NMPA film is remarkably low, with an adhesion strength of approximately 4.7 kPa for a 1 × 1 cm2 ice column. After undergoing rigorous durability tests, including xenon lamp weathering test, pressure resistance test, repeated adhesive tape testing, xenon lamp irradiation, water drop impact testing, and repeated brushing with hydrochloric acid and particles, the film's surface structure and superhydrophobic performance have remained exceptional. The photothermal superhydrophobic passive anti-icing and active deicing technology in this work rely on sustainable solar energy for efficient heat generation. It presents broad prospects for practical applications with advantages such as simple processing method, environmental friendliness, outstanding anti-icing effects, and exceptional durability.

Effect of aloe-vera coating on the quality of mechanically damaged zucchini during long-term storage

Zucchini is susceptible to mechanical damage, which can occur during postharvest operations and leads to produce quality reduction. Bruising is the most common type of mechanical damage that could result in economic losses due to its effect on the appearance and shelf life of produce. This study aims to examine the effect of bruising and coating on the quality parameters of zucchini. Zucchini was bruised through the drop impact test which produced mechanical damage with an impact energy of 0.353 J. Other zucchini samples were not bruised and set as control. Half of the samples were coated with aloe vera gel. The samples were kept at 5, 10, and 22 °C for 24 days. The effect of impact bruising, storage conditions, and coating on the bruising size and other quality attributes (weight, color, firmness, pH, and total soluble solids) was investigated. The results showed that bruising parameters were dependent on storage duration and coating. At all tested storage conditions, coating with aloe vera helped regulate the weight and yellowness changes in zucchini samples during the storage period. Storage at 10 °C showed the least reduction in weight on all treated and control samples compared to other storage conditions. The redness and greenness (a* value) color changes in all tested zucchini samples were steadily increasing at 22 °C. Coated, non-bruised zucchinis showed a gradual increment in total soluble solids and were highly maintained at 10 °C storage condition. A reduction in the firmness of zucchini was significantly observed due to storage duration. Meanwhile, pH increased but was not significantly affected by any of the tested factors. Moreover, this study indicated the importance of both aloe vera coating and storage management in preserving zucchini quality parameters and extending its shelf life. Hence, coating zucchini should be considered when attempting to increase its shelf life. Moreover, the findings of the study can provide baseline data to understand the mechanism of mechanical damage on the quality of zucchini.

Experimental investigation of brain contusion characteristics and dynamic response in low-age children using an animal model

IntroductionBrain contusion is a prevalent traumatic brain injury (TBI) in low-age children, bearing the potential for coma and fatality. Hence, it is imperative to undertake comprehensive research in this field. MethodsThis study employed 4-week-old piglets as surrogates for children and introduced self-designed devices for both free-fall drop impact tests and drop-hammer impact tests. The study explored the characteristics of brain contusion and dynamic responses of brain under these distinct testing conditions. ResultsBrain contusions induced by free-fall and drop-hammer conditions both were categorized as the coup injury, except that slight difference in the contusion location was observed, with contusion occurring mainly in the surrounding regions beneath the impact location under free-fall condition and the region just right beneath the impact location under drop-hammer condition. Analysis of impact force and intracranial pressure (ICP) curves indicated similar trends in impact forces under both conditions, yet different trends in ICPs. Further examination of the peak impact forces and ICPs elucidated that, with increasing impact energy, the former followed a combined power and first-order polynomial function, while the latter adhered to a power function. The brain contusion was induced at the height (energy) of 2 m (17.2 J), but not at the heights of 0.4, 0.7, 1, 1.35 and 1.7 m, when the vertex of the piglet head collided with a rigid plate. In the case of a cylindrical rigid hammer (cross-sectional area constituting 40 % of the parietal bone) striking the head, the brain contusion was observed under the energy of 21.9 J, but not under energies of 8.1 J, 12.7 J and 20.3 J. Notably, the incidence of brain contusion was more pronounced under the free-fall condition. ConclusionsThese findings not only facilitate a comprehensive understanding of brain contusion dynamics in pediatric TBIs, but also contribute to the validation of theories and finite element models for piglet heads, which are commonly employed as surrogates for children.

Experimental Analysis and Finite Element Modeling of S-Core Sandwich Panel Composites Drop Impact Response

Sandwich panel composites have several applications in material technology. The sandwich panel composite material is constructed of stainless steel-316 for the top and bottom plates, aluminum 1050A-0 for the core, and DP-8405 acrylic adhesive for the binding element. The impact behavior of S-core composite sandwich panels was examined using low-velocity drop impact tests and finite element models. Finite element models have been created to characterize the influence of composite element bending behavior on variations. The specific flexural modulus and strength of composite S-core sandwich structures are equivalent to those found in the literature for core structures. As a result, the minimum weight design served as a guideline for producing weight and density-efficient hybrid composite sandwich panels. The energy absorbed in the test findings rose between 15.15% and 30% as the core thickness grew and between 3.571% and 41.34% as the core arrays changed. Impact load-bearing capability increases with varied core heights and array designs.

Design and optimization of circular honeycomb lower limb protection device under blast impact

A circular honeycomb lower limb protection device was proposed to reduce the damage to the occupant’s lower limbs under a vehicle under-belly blast. First, a local equivalent model of the occupant-restraint system was established, and drop impact tests and theory were used to validate the model’s accuracy. Then, under the same mass, the protection performance of eight lower limb protection devices using circular honeycomb, hexagonal honeycomb, reentrant honeycomb, etc., as sandwiches were compared. It was found that the lower limb protection device with a circular honeycomb sandwich provides the best defence for lower limbs. Subsequently, the effect of gradient structure settings and dimensional parameters on the protection performance of circular honeycomb lower limb protection devices was investigated. Finally, multi-objective optimization has been carried out to further improve its protection performance. The results indicated that the protection performance of the lower limb protection device could be effectively improved by reasonably selecting the cell arrangement, gradient type and gradient interval of the honeycomb sandwich. When the optimized lower limb protection device was employed, the occupant's left and right lower tibial peak forces were decreased to 3.67 kN and 3.55 kN, respectively. Compared with the initial design, the optimized lower limb protection device reduced the left and right lower tibial peak forces by 21.1% and 23.8%, respectively, and the total mass decreased by 51.5%.

Strength, durability, and impact behavior of recycled aggregate concrete with polypropylene aggregate

Massive consumption and production of plastic is expected to have a significant environmental impact in the near future. Plastic waste from landfills can be refined and recycled as aggregates in concrete through subsequent processing. Several studies have already been conducted using plastic scraps as aggregate in concrete. However, more research is needed before it can be incorporated into structural concrete. Therefore, this study aims to investigate the static and dynamic behavior of concrete made with polypropylene plastic aggregate (PPA) obtained from waste plastic materials. Natural coarse aggregate (NCA) and recycled concrete aggregate (RCA) are partially replaced with PPA in this study and drop impact tests are performed after the samples are exposed to room and elevated temperatures (200 °C and 400 °C). PPA replacement percentages are 0, 5, 10, and 15 %. The drop impact test is performed on both cylinders (150 mm × 63.5 mm) and beams (100 × 100 × 500 mm) specimens. Different mechanical and durability tests are also investigated. The impact energy decreases by up to 68 percent as the PPA percentage increases at room temperature. Furthermore, when the specimens are heated to 200 °C or 400 °C, the impact blows are significantly reduced (6–13 no). After being heated to 200 °C and 400 °C, the 15 percent NCA replaced cylinder loses 87 percent and 91 percent of its impact energy, respectively. In terms of mass loss, the control cylinder has a higher loss than the PPA cylinders, indicating that the presence of PPA in concrete causes less damage. In terms of mechanical properties, the 5 percent PPA-based concrete outperforms the control. Depending on the concrete age and coarse aggregate types, a 5 % PPA content increases compressive strength by up to 11.6 percent. In terms of durability, the water absorption tendency increases with increasing PPA content, and all-natural PP concrete (NPC) and recycled PP concrete (RPC) exhibit moderate to very low chloride ion penetrability. Overall, it is proposed that 5 % PPA be used with NCA and RCA for structural applications.

Dropping impact experiment of crisp pears and contact pressure analysis

ABSTRACT Efforts have been made to streamline the abstract as follows. If further changes are made we are concerned that the integrity of the content may be compromised. We hope you will understand. This study aimed to investigate the impact damage experienced by Pucheng crisp pears during various stages, including harvest, transportation, and processing. Drop impact tests were conducted on pears, considering drop height and collision contact material as factors influencing damage. The bruise area was used as an indicator for damage evaluation. Additionally, the pressure-sensitive film technique was employed to measure the contact stress distribution characteristics of Pucheng crisp pears after the drop impact. The relationship between contact stress distribution and damage area was examined, and the stress area range close to the damage area was determined. The results revealed that the damage area of pears increased linearly with the increasing drop height. Among the four contact materials, foam board exhibited the best cushioning properties, with a maximum safe drop height of 20 cm. The pressure distribution tended to follow a normal distribution, with a pressure range of 0.2-0.3 MPa covering the largest area, corresponding to the majority of the bruise area on the pears. Furthermore, the pressure area and average pressure were found to be related to the severity of bruising. When pears were dropped onto steel, rubber plate and corrugated board, for the former two the stress area exceeding 0.2 MPa closely approximated the damage area, with an average relative error of 7.2%. For the latter, the closest range was above 0.3 MPa, with an average relative error of 3.6%. However, when dropped onto foam board, the average relative error was 75%. This research provides valuable insights for designing packaging tools to minimize damage and serves as a theoretical basis for predicting and assessing pear bruise area using finite element analysis.

THE EFFECTS OF ADDITIVE ON THE IMPACT ABSORPTION CAPABILITY OF MAGNETORHEOLOGICAL ELASTOMER

Magnetorheological elastomer (MRE) is a smart material whose its damping and stiffness characteristics change when exposed to a magnetic field. MRE usually contains rubber and ferrous particles. Other materials such as additives, can improve physical properties of MRE during cyclic loading. However, limited research has been conducted into the effect of incorporating these additives on MRE performance when subjected to impact loading. Additives can change the MRE’s structure such as stiffness and enhance its damping properties, especially its impact absorption capabilities. This study focuses on the force-displacement characteristics of additives and their relationships with MRE containing additives in impact absorption applications. This study uses ferrite, zinc, aluminum, and copper as additives in MREs fabrication and subjects the MREs to a drop impact test at varying applied currents of 0, 0.5, 1.0, 1.5, and 2.0 ampere. The experimental results show that the MRE containing ferrite has the highest average impact absorption capability of 2.24 Nm, followed by zinc, aluminum, and copper.

Indentation and impact response of conventional, auxetic, and shear thickening gel infused auxetic closed cell foam

Auxetic closed cell foams, and highly viscoelastic foams, both show potential to improve impact protection. Specifically, auxetics adapt to the shape of impacting bodies, while highly viscoelastic foams stiffen during severe impacts. So, we made auxetic closed cell foam sheets, including those that were infused with (highly viscoelastic) shear thickening gel (STG). We then undertook comparative quasistatic and impact (drop) tests. Quasistatic tests included compression, tension and indentation. Impact tests were with a flat faced impactor at energies of 1, 3 and 5 J, and a 50 mm diameter hemisphere at 1 and 3 J. Poisson’s ratios of the foams were obtained by optical full field strain measurement. An analytical model was used to separate the contribution of the various measured orthotropic properties during the hemispherical impact and indentation tests. The Poisson’s ratios of the converted foams (both with and without STG) were close to zero or marginally negative when measured through thickness. Planar values of Poisson’s ratio (measured in tension) were as low as −0.6. Through thickness Young’s moduli of the converted foams were 0.5 MPa, and planar moduli were ∼12 times higher. The auxetic foams outperformed the unconverted ones during the more severe impacts, exhibiting about half the peak force during the 3 J hemispherical impacts (2.5 vs. 5 kN). The reduction in peak force was related to a measured doubling in indentation resistance for the auxetic foam. The analytical model suggests that 7%–15% of the measured doubling in indentation resistance was due to (negative) Poisson’s ratio. Infusing the auxetic foams with STG caused, at best, a marginal reduction in peak impact force, attributed to low and non-uniform levels of infusion.

The structural and non–linear dynamic analysis for radioactive waste container

In recent years, the development of radioactive waste containers for nuclear facility decommissioning and dismantling is a critical issue because the Taiwan domestic boiling water reactor nuclear power plant is going to be decommissioned. The main purpose of this research is to design a metal container that meets the structural requirements of related regulations. At first, the shielding analysis was performed by varying dimensions of radioactive waste to determine the storage efficiency of the container. Then, a series of structural analyses for operational and accidental conditions of the container with full load were conducted, such as lifting, stacking, and drop impact conditions. On the other hand, the field drop impact tests were carried out to ensure structural integrity. The present research demonstrates the structural safety of the developed container for decommissioned nuclear facilities in Taiwan.

Hysteresis Behavior Modeling of Magnetorheological Elastomers under Impact Loading Using a Multilayer Exponential-Based Preisach Model Enhanced with Particle Swarm Optimization.

Magnetorheological elastomers (MREs) are a type of smart material that can change their mechanical properties in response to external magnetic fields. These unique properties make them ideal for various applications, including vibration control, noise reduction, and shock absorption. This paper presents an approach for modeling the impact behavior of MREs. The proposed model uses a combination of exponential functions arranged in a multi-layer Preisach model to capture the nonlinear behavior of MREs under impact loads. The model is trained using particle swarm optimization (PSO) and validated using experimental data from drop impact tests conducted on MRE samples under various magnetic field strengths. The results demonstrate that the proposed model can accurately predict the impact behavior of MREs, making it a useful tool for designing MRE-based devices that require precise control of their impact response. The model's response closely matches the experimental data with a maximum prediction error of 10% or less. Furthermore, the interpolated model's response is in agreement with the experimental data with a maximum percentage error of less than 8.5%.

Evaluation of thermal and mechanical properties of continuous fiberglass reinforced thermoplastic composite fabricated by fused deposition modeling

AbstractFused deposition modeling (FDM) is utilized to fabricate continuous fiber‐reinforced thermoplastic composites (CFRTPCs) and can be considered an alternative to conventional processes. In present study, the specimens are 3D printed in Markforged Mark Two composite 3D printer by considering Onyx as matrix material and fiberglass as reinforcing material. Thermal gravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) of Onyx and fiberglass materials are done to investigate their thermal stability and composition. The effect of infill pattern and fiber orientation on tensile and drop impact properties are examined. The TGA results show that the initial decomposition in Onyx is higher compared to fiberglass due to more evaporation of moisture content in Onyx. The FTIR analysis confirmed that the spectrum for both materials is same within the range of wave number from 4000 to 1500 cm−1. The tensile test results represent that the specimen with triangular infill pattern and 0°/90° fiber orientation resulted in maximum tensile strength of 148.01 MPa and the drop impact test results showed that the triangular infill pattern with 0°/90° fiber orientation absorbs maximum impact energy which is 14.90% and 8.98% higher compared to honeycomb and rectangular pattern respectively. Further, the fracture behavior study is carried out based on the optical images of fractured specimens.

Energy absorption behavior of oil palm empty fruit bunch fiber-reinforced composites subjected to low-velocity impact

In this study, oil palm empty fruit bunch (OPEFB)-reinforced composites were subjected to a low-velocity impact test to study their energy absorption characteristics. Two sets of OPEFB-reinforced composite specimens were used, comprising 30:70 and 40:60 fiber/epoxy fractions. One set of specimens was treated with a 3% NaOH solution. The drop impact responses, fragmentation characteristics, energy absorptions, and residual strengths of both sets of specimens were analyzed. Drop impact tests were performed using three different energy levels, namely, 10, 13, and 16 J. In general, the results indicated that all the untreated specimens absorbed higher energy than that of the treated specimens, thus suffering severe surface and structural damage. This result is attributed to the treated specimens providing a better interlocking mechanism between the matrix and fibers and dissipating the impact energy through the impactor. Regarding fiber loading, all the 30:70 fiber/epoxy composites exhibited slightly less energy absorption than the 40:60 fiber/epoxy composites.

Design, Manufacturing, and Numerical Characterization of Hybrid Fiber Reinforced Polymer under Dynamic Loads

In the present work, the response of composite hybrid laminates made of carbon and glass fibers in different stacking configurations was tested under low-velocity impact loads. Experimental drop impact tests were conducted on three different stacking sequences and three rising impact energy levels. The results from the tests were assumed for the development and validation of a numerical impact model reproducing for each stacking sequence and all the impact energy levels, the laminates impact response. The validated model investigated the occurred damage mechanisms, their distribution in the panel thickness and their extension on the plane of the laminate. Depending on the stacking sequence and the impact energy level, the energy absorption capacity was related to the dominant damage mechanism. The percentage contribution of interlaminar and intralaminar damages was presented and conclusions were drawn about the influence of stacking sequences on energy absorption and damage characteristics.