Interlaminar Shear Strength Tests Research Articles

PROCESSING PARAMETERS OPTIMIZATION OF VACUUM-BAGGING PREFORMING IN OVEN CURE FOR INTER-LAMINAR SHEAR STRENGTH (ILSS) IN GLASS/EPOXY COMPOSITE LAMINATE

Autoclave had been restricted to immense production expenses and overabundant residual stress. These disadvantages had prompted development on the alternative of out-of-autoclave (OoA) processing. The optimization on vacuum-bagging-only (VBO) pre-forming process in producing high inter-laminar shear strength (ILSS) of composite laminate was proposed. The effects of individual and combined pre-forming parameters of VBO-oven cure processing for the conventional low-cost glass/epoxy composite material towards ILSS of cured laminates were quantified. 20 composite panels were manufactured following the designated parameter combinations based on central composite design in fractional factorial for response surface model. Three factors of vacuum debulk duration, edge breather number of sides and intensifier weight were investigated. For validation, two laminates without additional processing parameters were produced via oven (baseline) and autoclave. ILSS test was conducted based on ASTM D 2344. The interaction between combined parameters was analyzed using analysis of variance (ANOVA). Lowest ILSS was found in laminates where intensifier was absent, while highest ILSS was measured with edge breather, debulk and intensifier at different levels. An optimum combination of 30 minutes debulk, each sides of edge breather and 1kg intensifier were validated to produce laminate with highest ILSS of 38.96 MPa, which was 23.53% higher than baseline laminate.

Durability of concrete-embedded GFRP bars after 20 years of tidal zone exposure: Correlation with accelerated aging tests

The application of non-metallic glass fiber-reinforced polymer (GFRP) bars as embedded reinforcement in reinforced concrete (RC) has been of great interest among researchers and practicing engineers alike, owing to its properties such as high strength-to-weight ratio and corrosion resistance. This study investigated the long-term performance of ribbed (RB) and sand-coated (SC) GFRP bars embedded in concrete columns exposed to harsh seawater conditions for approximately 20 years. The bars extracted from the concrete elements were tested to evaluate strength retention based on ASTM standard transverse and interlaminar shear strength tests. After the long-term field exposure, the ribbed and sand-coated GFRP bars exhibited 82.5 % and 79.4 % transverse shear strength retention, and 84.4 % and 78.1 % interlaminar shear strength retention, respectively, which corresponds to approximately 5 months of exposure in the accelerated solution specified by ACI 440.3R-12 guide. Scanning electron microscopy analyses revealed the extent of damage in the fibers, the matrix, and their interface, which validated the degradation in the mechanical strength of the exposed GFRP bars. Finally, correlations between long-term and accelerated exposure test conditions were developed to predict transverse and interlaminar shear strength in the field based on laboratory conditioning investigations.

Investigation of mechanical properties and self‐healing efficiency of carbon fibers composites infused with unsaturated polyester vitrimer

AbstractUnsaturated polyester resins (UPR) are widely in composite manufacturing, particularly in the energy, wind, and construction sectors. When these composites sustain damage, defects or cracks, several methodologies are employed to heal and repair them to extend their lifespan while reducing environmental impacts. In this work, the use of vitrimeric UPR (UPRv) as a matrix for carbon fiber composite, was investigated in terms of healing efficiency by mechanical and thermal properties. Flexural and interlaminar shear strength tests revealed healing efficiencies exceeding 40% and 90%, respectively. These results were attributed to the transesterification exchange occurring within the crosslinked networks of UPRv. As described in our previous work, the incorporation of “Covalent Adaptable Networks (CANs)” enables the conversion of commercial thermoset (UPR) into vitrimeric resins, thereby providing reprocessing and healing capabilities. Furthermore, a comparison between pristine and healed composites with Mode I DCB and Mode II ENF tests, confirm how the introduction of vitrimer in composite facilitates the manufacturing of a self‐healing product, with a significant recovery of the original properties.Highlights Application of a previous synthetized vitrimeric unsaturated polyester resin (UPRv)—fabrication of CF's composites reinforced with UPRv—investigation of the self‐healing property of the developed laminates—potential application as green and sustainable composites.

In-line monitoring of cryogenic three-point bending test of fiber-reinforced composites using acoustic emission

Remotely in-line monitored acoustic emission (AE) of interlaminar shear strength tests in a 3-point bending test of fiber-reinforced polymer composites (FRP) conducted under cryogenic conditions in liquid nitrogen (LN2) were studied. The AE sensors were reversibly mounted at the outer components of the testing machine to thermally decouple them from the cryogenic area and use AE signal transmission through the testing machine structure as a waveguide. The damage mechanisms and effect of the cryogenic temperature were studied at 296 K room temperature (RT) and in LN2 at 77 K, considering machine and process noises. The correlation of machine data with acoustics and the AE hit analysis revealed matrix cracking as the most frequent damage mechanism under both conditions but with different failure mechanisms. At RT and applying higher loads, the most damage suddenly occurred, and the specimen failed. In LN2, the damage occurred continuously from the beginning of testing. The amount of fiber failure increased, and the AE feature ranges enlarged. This study presents a method by AE for remote monitoring the mechanical response of FRP in cryogenic fluids such as liquid hydrogen. The method provides a new approach to support the more efficient development of FRP materials for storage vessel structures and structural health monitoring systems.

Influence of layering sequence on performance of jute/wool epoxy hybrid composites: a comparative study with automotive plastic

Natural fibres such as Jute and Wool are increasingly being used in fibre reinforced polymer composites, hence progressively supplanting synthetic fibres. Combining these two unique natural fibers would improve the performance of composites used in secondary structural applications. This study is intended to investigate the effects of Jute and Wool fiber arrangement on mechanical properties in an epoxy matrix. In order to achieve this, hand layup was employed to fabricate composite laminates consisting of four layered fabric layers stacked in sequences, as Jute/Wool/Wool/Jute (JW1), Wool/Jute/Jute/Wool (JW2), Jute/Wool/Jute/Wool (JW3), and Jute/Jute/Wool/Wool (JW4). Effect of these stacking sequences on the properties of Natural Fibre Hybrid Composites (NFHCs) was evaluated by conducting a series of standardized tests such as Flexural, Interlaminar Shear Strength (ILSS), Impact and Single End Notch Bend (SENB) tests, as per ASTM standards. On the other hand an automobile interior thermoplastic material was evaluated for different mechanical properties and compared with hybrid Jute-Wool composite. Experimental results showed that the JW1 composite, exhibited superior mechanical properties because it has tailored with a Wool fabric at the core and Jute fabric on its outer surface. Hence, JW1 had a remarkable tensile strength of 40 MPa, a maximum flexural strength of 99 MPa and extremely high interlaminar shear strength (ILSS) of 3.09 MPa. In addition to this, JW1 also had high fracture toughness, measuring around 72 M P a m 1 /2, and impressive impact strength of 85 J/m2. Furthermore, scanning electron microscope (SEM) photo images confirmed that the presence of strong bonding between the fibres and matrix in JW1 composite exhibited and overall improvement of mechanical performance by 82% when compared with other combinations (JW2, JW3, and JW4) including automotive plastics.

The Effect of Carbon-Based Nanofillers on Cryogenic Temperature Mechanical Properties of CFRPs.

In the present work, the effects of carbon-based nanofillers (0.5 wt%), i.e., graphene nanoplatelets (GNPs), carbon nanofibers (CNFs), and carbon nanotubes (CNTs), on the cryogenic temperature (77 K) mechanical properties of carbon fiber reinforced polymers (CFRPs) were investigated. The study utilized an ex situ conditioning method for cryogenic tests. The nanofillers were mixed with the epoxy matrix by a solvent-free fluidized bed mixing technique (FBM), while unidirectional carbon fibers were impregnated with the resulting nanocomposites to manufacture CFRP samples. Optical microscopy was employed to analyze the dispersion of the carbon-based fillers within the matrix, revealing a homogeneous distribution in nanocomposites containing GNPs and CNFs. Fracture toughness tests confirmed the homogeneity of the GNP-loaded systems, showing an improvement in the stress intensity factor (KC) by 13.2% and 14.7% compared to the unmodified matrix at RT (25 °C) and 77 K, respectively; moreover, flexural tests demonstrated a general increase in flexural strength with the presence of carbon-based nanofillers at both temperature levels (RT and 77 K). Additionally, interlaminar shear strength (ILSS) tests were performed and analyzed using the same ex situ conditioning method.

The effect of graphene oxide on thermal, electrical, and mechanical properties of carbon/epoxy composites: Towards multifunctional composite material

AbstractThe focus of this research work is to investigate the influence of graphene oxide (GO) on the mechanical, thermal, and electrical properties of carbon fiber‐reinforced polymer (CFRP) composites. The solvent mixing method with the new addition of a mixing stage is introduced for uniform distribution of graphene oxide in polymer. Different weight percentages of graphene oxide (1%, 1.5%, and 2%) were incorporated into the epoxy matrix, and the resulting composites were subjected to electrical conductivity, thermal conductivity, and interlaminar shear strength (ILSS) testing. The findings revealed a positive influence on material properties with the percentage of GO. Especially, the electrical conductivity and ILSS values reached up to 7.05 S/m and 11.03 MPa, respectively, when 1.5% GO by weight of the resin was added. The improvement in ILSS reported by 40% compared to the neat CFRP, and this increment was attributed to enhanced bonding between the epoxy matrix and carbon fabric. Maximum thermal conductivity of 1.04 W/m°K obtained at 1% GO filler, which is 15% higher than neat epoxy composite. Overall, these results illustrate the potential of GO as a promising filler to improve the electrical, thermal, and mechanical properties of CFRP composites. Proper optimization of graphene content in a polymer is needed to achieve the best multifunctional composite materials.Highlights The new solvent mixing method is introduced for uniform distribution of graphene oxide in polymer. Maximum thermal and electrical conductivity obtained at different percentages of graphene content in composite. Positive improvement is observed in mechanical, thermal, and electrical at a specific percentage of graphene in the composite. Proper optimization of nanofiller content in composite is needed to assess for maximum performance.

Effect of silane coupling grafted polyethylene terephthalate foam and areca fruit fiber reinforced chitin modified vinyl ester prosthetic composite on thermal and water accelerated aging conditions

AbstractThe primary aim of this research work was to develop a lightweight vinyl ester based prosthetic composite with silane treated Polyethylene terephthalate (PET) foam and areca fiber and how the silane surface treatment process influence the laminar adhesion against to accelerated aging conditions. Both the foam (3 mm) and fiber is silane‐treated via aqueous solution method and the composites were subjected to accelerate aging via temperature (40 and 50°C) as well as sea and rain water. The developed composites were evaluated based on American society of testing of materials (ASTM) standards and the results revealed a consistent stability in tensile strength for post‐silane treated composites on both aging conditions. Particularly, the interlaminar shear strength (ILSS) test emphasized that the silane treated reinforcements has high resistance against delamination. Similarly, flammability test demonstrated sustained fire‐resistant properties in both horizontal and vertical orientations, with negligible variations in flame propagation speed. Thermal conductivity test revealed the intricate interplay of PET core and areca fiber on heat transfer. Thus, from results it is evident that the silane surface treatment helped to maintain the laminates adhere with matrix in spite of the accelerated aging conditions such as prolonged heat exposition as well as water immersion. These findings contribute valuable insights into the load bearing performance of the lightweight composite materials in human prosthetic applications where prolonged heat and water aging happened frequently.Highlights Lightweight polymer foam‐areca fiber prosthetic composites prepared and tested for accelerated weather conditions PET foam and areca fiber is silane surface treated using amino‐silane Treated foam and fiber maintained mechanical properties under aged condition Treated foam and fiber maintained flammability properties under aged condition Silane treated foam and fiber maintained good thermal conductivity under aged condition

Significant Effect of Vacuum Bagging Processing on Inter-Laminar Shear Strength and Voids of Composite in Oven Cure

Autoclave had been constrained to longer time consumption, higher production costs and excessive residual stress. The challenges regarding with out-of-autoclave (OOA) cure involved the need to devise the techniques in preserving high quality of composite product during service life. The current work was proposed to quantify the impact and influence of pre-forming parameter variations in vacuum-bagging-only with oven curing (VBO-oven cure) of OOA manufacturing composite processing on the inter-laminar shear strength (ILSS) of low-cost conventional composite laminates. The relationship of ILSS and void quality characteristics was also investigated. Series of conventional lower-cost glass/epoxy aerospace-grade material was fabricated using 16 different processing routes in conventional oven. Burn-off and ILSS test was conducted based on ASTM standard to compute the ILSS and void content of cured laminates. Scanning electron microscopy (SEM) analysis was performed on the post-test ILSS coupons to evaluate the relationship between void characteristics and ILSS. Results indicated that mould release type and intensifier contributed highest effects towards ILSS of approximately 31.3% and 27.6%, respectively. The assessment of ILSS-void relationship was further carried out and it was found that void geometry has a greater influence towards ILSS than the void content of composite laminate. The combination of these factors in processing routes yielded the lowest ILSS and void content at 24.85 MPa and 5.74%, respectively. These concluded that an optimized manufacturing technique could be expanded from the optimum settings of these processing parameters.

Effect of sizing agents on tensile properties of carbon fiber filament wound structures

In order to evaluate the effects of sizing agents on the wettability, strength loss, and properties of final filament wound structures during filament winding of carbon fibers, three types of sizing agent based on epoxy, epoxy + polyester, and epoxy + polyurethane were used to treat carbon fibers, the surface properties of carbon fiber samples after treatment were evaluated using SEM, infrared spectroscopy, dynamic contact angle analysis, and interlaminar shear strength (ILSS) test, the strength loss caused by fiber damage during filament winding was quantitatively analyzed, and the strength properties of the filament wound structures were characterized by NOL ring test. The results showed that the sizing agent treatment only slightly improved the surface free energy and ILSS of carbon fibers, but it had obvious influence on the strength loss rate of carbon fiber bundles. Added polyester or polyurethane in epoxy-based sizing may improve its protective effect for carbon fiber, and thus decrease strength loss during winding process, result in better tensile properties of carbon fiber filament wound structures.

Influence of compaction and curing in the Automated Fiber Placement Process on the mechanical performance of composite laminates

This paper investigates the effect of compaction and curing states on the mechanical properties and void content of AFP-manufactured laminates. For the mechanical characterization, tensile tests, 4-point-bending tests and interlaminar shear strength (ILSS) tests were applied. The internal structure was evaluated via micro CT. For the surface structure evaluation, an optical profilometer was used. The void content was determined via segmentation of the micro CT images. The paper is subdivided into the description of the applied materials and methods, the results and their discussion and a conclusion. The study showcases the potential of AFP-manufactured aerospace composites to attain high-quality results even without the need for an autoclave, making them well-suited for unmanned applications.

Laser In Situ Joining as a Novel Approach for Joining Large‐Scale Thermoplastic Carbon Fiber‐Reinforced Polymer Aircraft Structures

Thermoplastic matrix composites are a viable option to reduce the carbon footprint during the life of an aircraft due to their ability to be molten and resolidified again. Tape‐based layup processes, such as automated tape placement, are well‐examined but have not seen extensive use in large‐scale joining applications, since they have to be processed layer‐by‐layer. In contrast, the advanced laser in situ joining method (CONTIjoin) utilizes fully consolidated and cut‐to‐size multilayered laminates, enabling the continuous layup of tailored laminates aligned with the mechanical application requirements. Herein, sample joints are manufactured using CONTIjoin technology, describing the general process principle, and are compared with samples produced using a standard heat press process. The base material, carbon fiber‐reinforced LMPAEK (low‐melt polyaryletherketone) is characterized using infrared spectroscopy. Using a 3.5 kW carbon dioxide (CO2) laser (10.6 μm wavelength) coupled with highly dynamic beam deflection, multidirectional reinforced laminates with up to six plies are processed to produce 24‐ply plates. The influence of joining temperatures up to 400 °C on the joint quality is investigated. Cross‐cuts are examined and interlaminar shear strength tests are conducted. With CONTIjoin, maximum strengths of 48.5 MPa are observed, reaching over 90% of the heat press reference.

Interfacial properties of carbon fiber‐reinforced biobased resin composites by single fiber fragmentation, fiber push‐out, and interlaminar shear strength

AbstractThe present study examines the interfacial properties of carbon fiber biobased resin composites by comparing the test methods such as the single fiber fragmentation test, fiber push‐out test, and interlaminar shear strength test. The composites were fabricated using a cold vacuum‐assisted resin infusion method for the preparation of fiber push‐out and interlaminar shear test specimens. The interfacial adhesion from the three different test methods is analyzed and compared to determine their relative effectiveness in evaluating interfacial adhesion. Plasma treatment is performed on the carbon fibers and the interfacial shear stress is evaluated by conducting the push‐out test. The surface characterization of the carbon fibers is done by scanning electron microscopy and x‐ray photoelectron spectroscopy to investigate the influence of the plasma treatment on the fiber surface. Plasma treatment resulted in significant improvement in the interfacial adhesion between the fiber and matrix.Highlights Analysis and comparison of interfacial adhesion by several test methods. Single fiber fragmentation and push‐out tests with IFSS of 40.5 and 42.2 MPa. Plasma surface treatment improved the IFSS by 88.1%. Surface characterization of treated and untreated fibers by SEM and XPS.

Surface modification of aramid fiber by cascade process with atmospheric plasma and TDI grafting

Aramid fiber (AF)/epoxy composites are often used as mechanical and insulating materials for ultra-high voltage gas-insulated switchgear (GIS) insulation pull rods. However, the product performance is believed to be restricted by the poor adhesion between AF and the resin matrix, affecting the operation reliability of GIS. In this work, a cascade process was applied to modify the AF surface to improve interfacial behavior. The AF was first treated with air dielectric barrier discharge at atmospheric pressure to obtain a rough surface and then reacted with toluene-2,4-diisocyanate (TDI) to introduce polar functional groups onto the surface. The plasma discharge power and treatment time were investigated as major parameters, and the aging effect was studied. The modified AF was characterized by scanning electron microscope, Fourier transform infrared spectrometer, x-ray photoelectron spectroscopy, atomic force microscope, and filament yarn tensile test. The interfacial behavior of the AF/epoxy composite was analyzed by interfacial shear strength (IFSS) test of micro-bond specimen and interlaminar shear strength (ILSS) test of Naval Ordnance Laboratory rings. Experimental results showed that polar functional groups were introduced onto the AF surface. The IFSS and ILSS of AF/epoxy composite were increased by 32.8% and 20.2% at most, respectively, and the tensile strength of the AF was mostly preserved. Moreover, with the increase in plasma discharge power, the interfacial strength of the modified AF/epoxy interface increased firstly and then decreased. The AF modified by TDI retained a relatively good modification effect after aging for some time. This study presents a cascade process for the AF surface modification with simplicity, effectiveness, and resource-saving, which is suitable for industrial applications.

Fracture toughness response of glass/epoxy composite in symmetric and asymmetric design layup

Composites are used in transportation industries for their exceptional strength, reduced weight, and cost. Their performance depends upon many factors, such as stacking sequence, fiber volume fraction (FVF), etc. In the present work, glass/epoxy composites are prepared in symmetric (ɸn/θ2n/ɸn//ɸn/θ2n/ɸn) and asymmetric (θn/ɸ2n/θn//ɸn/θ2n/ɸn) configuration with FVF of 48.13 and 61.34%. The laminate performance was evaluated using interlaminar shear strength, flexural, and mode-II interlaminar fracture toughness tests. The results indicate that symmetric layup has better mechanical strength than asymmetric layup. The interlaminar shear strength, flexural, and fracture toughness of asymmetric layup were lower by 14.72–16.39, 12.54–16.72, and 11.92–17.98%, respectively. Further, low FVF specimens had better mechanical strength, and high FVF specimens showed lower strength by 3.67–5.56, 10.75–15.17, and 23.53–28.79%, respectively,

Failure prediction in a non-crimp basalt fibre reinforced epoxy composite

Failure analysis in non-crimp fabric (NCF) based fibre reinforced composite materials is challenging due to the complexity associated with multiaxial fabric architectures and the interaction of different failure modes. In this study an in-situ 3-point bend test under scanning electron microscopy (SEM) has been performed to analyse the failure behaviour of a NCF basalt epoxy composite manufactured by vacuum assisted resin transfer moulding (VaRTM) technique. The failure mechanisms observed during the in-situ 3-point bend test are compared to those from standard (ex-situ) flexure and interlaminar shear strength (ILSS) tests on the same material. Finite element analysis of each test configuration is also conducted to analyse the in-ply stress distributions and to predict the damage initiating stresses. The study reveals that fibre/matrix debonding leading to matrix cracking in the 90° sub-ply is the damage initiating failure mode, with final failure occurring due to fibre buckling in neighbouring 0° sub-plies. The finite element analysis reveals that matrix cracking in the 90° sub-ply is controlled by shear stresses ranging between 35 and 45 MPa.

Mechanical properties of carbon‐aramid hybrid fiber‐reinforced epoxy/poly(vinyl butyral) composites

AbstractCurrently, it is important to manufacture fiber‐reinforced epoxy matrix composites with high impact resistance besides their high strength and modulus values for industries such as automotive, aerospace, and aviation due to the brittle structure of epoxy. In this regard, we found the attractive results of the 0.5 wt% poly(vinyl butyral) (PVB)‐containing epoxy blend in terms of strength, Young's modulus, and impact resistance. These results substantially motivated us to manufacture fiber‐reinforced advanced epoxy/PVB matrix composites with 30–60 vol% carbon‐aramid fiber ratios. Flexural (three‐point bending) and tensile tests were performed to obtain strength and modulus values by measuring the force required to break the fiber‐reinforced composite specimens and elongation at break points. Interlaminar shear strength tests were performed by the short beam bending method by measuring the resistance of the composite to delamination. The Charpy impact test was used to measure the energy absorbed during crack formation and fracture propagation. The composites with PVB were generally superior to those without PVB (EPCs). Two types of findings were observed. First, PVB increased the tensile and flexural strength values substantially for the 30 and 40 vol% ratios, but the modulus values slightly decreased. Second, PVB also substantially increased the modulus values for the 50 vol% ratio besides the strength values. It was thought that this result could be attributed to the increase in the compatibility of the fiber/matrix for the 50 vol% ratio. These decreases for EPCs could be derived from the micro‐cracks and weaker interface between fiber and matrix.

Evaluation of interlaminar shear strength of co-cured fiber-reinforced fabric composite structures by lap joint method

Interlaminar shear strength (ILSS) indicates the resistance to interlaminar delamination of fiber-reinforced composite structures. The short beam shear (SBS) method has been commonly used for ILSS measurement, but unwanted failure modes can appear like a compressive or tensile failure in surface, and diagonal shear failure, causing poor measurement accuracy. The lap joint method has advantage that leading to a clear measurement of the shear strength. This paper proposed the lap joint method for extracting ILSS values of co-cured carbon or glass fiber-reinforced fabric composites (CFRC or GFRC) by minimizing the discrepancy between the experiment and finite element analysis of ILSS test. The lap joint method can compensate for the shortcomings of the SBS method. The calculated ILSS based on the lap joint method (LJ-ILSS) with correction factors showed similar values to the ILSS values by SBS method (SBS-ILSS) done by our work and other works of literature. Therefore, the proposed lap joint method has shown potential as a method to measure ILSS of the co-cured fiber-reinforced fabric composites, but also it can be extended to other types of fiber-reinforced composites.

Experimental study on the mechanical properties of CFRP/epoxy composite plates under seawater immersion

This study investigates the effects of seawater immersion at different temperatures on the degradation and viscoelastic behavior of carbon fiber-reinforced polymer (CFRP) composite plates. The present study investigated the effects of seawater immersion on the degradation of mechanical properties at 20 °C, 40 °C, and 60 °C of the carbon fiber reinforced polymer (CFRP) composite plates. The specimens were prepared by hand lay-up and cured under water for 7 days before immersion in artificial seawater for 6 months. Interlaminar shear strength (ILSS), tensile strength, and dynamic mechanical analysis (DMA) tests were performed periodically over a six-month exposure period, and scanning electron microscopy (SEM) was used to characterize aging damage and fracture morphology. The long-term shear behaviour of CFRP plates in seawater has been predicted using the Arrhenius theory. The results show that immersion in seawater significantly reduces ILSS, especially at higher temperatures and longer immersion times. However, the overall tensile properties of CFRP plates were not significantly affected. Dynamic mechanical analysis (DMA) revealed a decrease in the damping (tan δ), indicating a reduction of the fiber-matrix adhesion. The long-term life prediction showed that CFRP plates subjected to seawater immersion are susceptible to degradation, with a stable retention of interlaminar shear strength at 70% for the composite laminate.

High velocity impact response of carbon/epoxy composite laminates at cryogenic temperatures

Composite laminates are subjected to cryogenic temperatures in exposed aircraft structures during flight or in cryogenic tanks. The combination of cryogenic temperatures and high velocity impacts represents a threat to their integrity. This work investigates the behaviour of carbon-epoxy laminates under high velocity impacts (from 70 to 500 m/s) at room and cryogenic (-150 °C) temperatures and under two different plate orientations with respect to the projectile direction. The damage pattern of impacted specimens at low temperature, revealed by C-scan and X-ray tomography, exhibits a higher density of fiber breaks and shear matrix cracks which do not translate to a larger projected damaged area. The experimental analysis through interlaminar shear strength tests and the calculation of ply thermal stresses exclude the association of this particular pattern to damage mechanisms induced during the temperature decrease.