Specific Impact Strength Research Articles

Multi-functional hybrid sandwich composite structures: Evaluating damage mechanics and tolerance using compression after impacts

Building upon previous researches that introduced an innovative foam core hybrid-sandwich composite structure for radome applications, showcasing promising performance under low-velocity impacts (LVIs), this paper delves into the assessment of damage tolerance and mechanics through Compression After Impact (CAI) testing. The primary objective is to analyze disparities in damage tolerance, damage mechanisms, displacements, deformations, energy absorption, and residual strengths resulting from LVIs followed by CAIs on dissimilar materials on opposite faces of the hybrid structure. The extent of damage is evaluated through Computed Tomography (CT) scans. During LVIs, impacts on the S glass face sheets side demonstrated different energy dispersion and absorption mechanisms, leading to variations in indent damage depths and widths across all impact energy levels, unlike the impact damages observed from the Kevlar side. During CAI testing, this difference becomes more evident, with Kevlar specimens (KS3 & KS5) showing greater indentation depths and narrower widths, and S glass specimens (SK3 & SK5) experiencing buckling. These effects are due to the unique damage absorption and dispersion properties of Kevlar and S glass. These variations prompted an in-depth investigation of the structure using CAI to comprehend damage tolerance and mechanisms under compressive loads. This study, unparalleled in existing literature, proposes hybrid sandwich structures with superior specific impact and residual strength compared to various composite sandwich structures documented in published literature, expanding their utility beyond radomes.

Empirical and numerical analysis of damage tolerance in multifunctional hybrid sandwich fiber reinforced polymers composite structures for aerospace applications using compression after impact (CAI) testing

AbstractThis study presents a novel hybrid‐sandwich composite structure, customized for nose radomes applications, incorporating a foam core and distinct opposite face sheets composed of Kevlar and S‐Glass materials. Addressing in‐phase electromagnetic properties, UV protection and low velocity impact responses in our previously published work, this paper empirically and numerically investigates the damage tolerance response of the proposed structures through compression after impact (CAI) testing. The low velocity impacts (LVIs) on S‐Glass face sheets exhibited unique energy dispersion and absorption mechanisms, resulting in variations in indent damage depths and widths across all impact energy levels as compared with LVIs on Kevlar face sheets. After experimentally assessing the CAI behavior, a FE model is developed to predict CAI behavior, which closely aligned with experimental findings. This study, unprecedented in existing literature, proposes hybrid sandwich structures for nose radome aerospace applications, with superior specific impact and residual strength compared to various composite sandwich structures documented in the published literature expanding its utility beyond radomes.Highlights Innovative composites with superior low velocity impact response, tested for compression after impact performance. Designed for nose radomes found suitable for other impact prone applications. Experimental and numerical modeling showed comparable results. Major differences observed in damage mechanics, resistance, and tolerances.

Tensile and impact properties of thermoplastic fibre hybrid composites based on air textured commingling hybrid yarns composed of carbon/aramid/polyamide 6 and carbon/glass/polyamide 6 filament yarns

This paper reports a comparison of tensile and impact properties between carbon/aramid and carbon/glass fibres reinforced unidirectional thermoplastic hybrid composites. For this purpose, different hybrid composites were produced using commingled hybrid yarns of carbon/aramid/polyamide 6 filament yarns and carbon/glass/polyamide 6 filament yarns with a defined mixing ratio based on air texturing technology. The results show that the density and specific Youngs’ modulus of the composites changes linearly with the proportion of carbon/glass and carbon/aramid fibre in hybrid composites. The specific Young’s modulus decreases linearly with decreasing carbon fibre content in the hybrid composites. On the other hand, the specific tensile strength does not change linearly according to the rule of mixture and a negative hybridization effect can be observerd for both types of hybrid composites. Furthermore, the combination of carbon/aramid and carbon/glass fibres can increase the impact strength by approximately 204% and 218%, respectively, compared to the composite reinforced by CF only. Although the specific tensile strength and specific impact strength of carbon/aramid reinforced hybrid composites are higher than those of CF/GF hybrid composites due to the lower density of carbon/glass hybrid composites, the potential impact strength achievable in hybrid composites is higher with the carbon/glass combination than with the carbon/aramid combination.

Investigating damage resistance in aerospace radome applications: Experimental analysis of hybrid sandwich composites

This research introduces an innovative hybrid sandwich composite structure tailored for specific applications, featuring a foam core and dissimilar face sheets made of Kevlar and S-Glass materials to address in-phase electromagnetic properties, UV protection, and impact response. Building on our prior work on design optimization for electromagnetic performance and aero/inertial loading, this paper investigates the low-velocity impacts (LVIs) response of the composite structure through drop-weight testing at various energy levels. Utilizing computed tomography (CT) scanning for damage analysis, distinct failure modes were observed for different face sheet combinations, with notable variations (energy absorption characteristics) in damage depth and width between the S-Glass and Kevlar face sheets. This study, unprecedented in existing literature, proposes hybrid sandwich structures with superior specific impact strength compared to various composite sandwich structures documented in the published literature expanding its utility beyond radomes.

Circularity of new composites from recycled high density polyethylene and leather waste for automotive bumpers. Testing performance and environmental impact

New composite materials (suitable for automotive bumpers), composed of recycled high-density polyethylene (rHDPE) and leather buffing dust waste (BF) ranging from 20 to 50 wt%, were produced and investigated for mechanical properties. Optimal mechanical performance was achieved with composites containing 30 % wt BF. The environmental performance of automotive bumper production from both virgin and recycled HDPE reinforced with 30 % wt BF (HDPE-BF, rHDPE-BF) composites was compared to that of conventional polypropylene (PP) by performing a cradle to gate life cycle assessment.A component-based approach, instead of a comprehensive LCA assessment for the entire car was adopted using various functional units (FU) such as mass (FU1), volume (FU2), and volume of raw material fulfilling a specific impact strength requirement (FU3), thus enriching the paper with methodological discussions.The rHDPE-BF system provided better environmental performance compared to the virgin PP system, when considering both mass and volume-related functional units, mainly due to the avoidance of virgin polymer production. Even with the inclusion of the use phase in FU2 and a slightly higher density (+1.7 %) of composites than PP-based bumpers, the rHDPE system still provides better environmental performance (10 % less impact). The sensitivity analysis highlighted the significance of car type and final density of the bumper on the impact results. Finally, when using FU3, due to its higher impact strength, HDPE-BF system is clearly the best environmental alternative (50 % less impact) followed by rHDPE-BF system. In all cases, rising the content of recycled materials in the bumpers increases its circularity.The paper illustrates the importance of selecting a suitable functional unit, based on a specific application (i.e., automotive bumpers), to evaluate the environmental impact of new composite materials in comparison to traditional options. Expanding the assessment to encompass multiple functions provides a more accurate portrayal of reality but also introduces greater result uncertainty.

Comparative study of the mechanical properties of glass and Kevlar fiber-reinforced honeycomb composite

Honeycomb sandwich structures have wide range of applications in the aircraft, automobile, and satellite sectors due to their superior properties such as high specific strength, stiffness, energy absorption, and high impact strength. In this study, mechanical characteristics such as compression, three-point bending, and in-plane impact properties of 3D woven honeycomb composites produced from Kevlar and glass fiber were investigated. The focus of this research is to compare the mechanical performance of woven honeycomb composites developed from these two fibers with similar cell structures. The results revealed that Kevlar fiber honeycomb composite shows higher peak load and energy absorption for flatwise and edgewise compression while in three-point bending and in-plane impact, glass fiber honeycomb composite shows higher peak load, and impact energy absorption. The deformations shown in all the mechanical properties give the ductile behavior for Kevlar fiber and brittle behavior for glass fiber composite. The findings of the study suggest that the failure modes are mostly determined by the nature of the material itself.

High‐velocity impact behavior of nonwoven mats and unidirectional prepreg hemp and flax fibers reinforced hybrid biocomposites

AbstractHigh specific impact strength and stiffness are demanded in various applications, leading to the widespread utilization of fiber‐reinforced polymers. Synthetic fiber‐reinforced polymers have been used to meet these engineering requirements. However, the current popularity of biocomposites arises from their environmental friendliness, ease of availability, and affordability, making them a favored alternative to synthetic‐based fiber‐reinforced polymers. An assessment must be conducted to determine whether biocomposites can replace their synthetic fiber counterparts, necessitating a thorough investigation into their impact behavior. This study aims to unveil the impact performance of hybrid biocomposites made from unidirectional prepregs comprising flax/polypropylene fibers and nonwoven mats composed of hemp/polypropylene fibers. The impact performance of hybrid biocomposites has also been studied concerning the number of layers and stacking sequence. Eight different designs of biocomposite plates are manufactured through compression molding and subsequently subjected to high‐velocity impact tests. Additionally, numerical simulation using the FEM is utilized to model and analyze the impact behavior of one specimen. The test results indicate that each design possesses unique characteristics and impact behaviors differ.Highlights Adding prepreg significantly improved mechanical performance in the biocomposites. Performance enhancement varies depending on the stacking sequence. Adding multiple layers of UD prepregs enhances mat impact performance. Numerical simulations validate the Tsai‐Wu criterion for impact testing.

Process‐property relationship in polylactic acid composites reinforced by iron microparticles and 3D printed by fused filament fabrication

AbstractPolylactic acid (PLA) is the most widely used material in the fused filament fabrication (FFF) technique, which is a biocompatible thermoplastic. However, PLA's usefulness is limited by its narrow processing window and relatively low mechanical properties. Therefore, PLA composites have been developed to enhance its properties for FFF printing. A key challenge in producing composite parts via this method is to find the correlation between the mechanical properties of the parts and the process parameters. This knowledge is essential for optimizing the printing process to achieve the desired mechanical properties for composite parts industries such as aerospace, automotive, and medical, where high‐performance composite materials are crucial. The ability to control and predict the mechanical properties of FFF‐printed composite parts is critical for their successful integration into these industries. In this study, the effect of nozzle temperature (NT), printing speed (PS), and nominal porosity (POR) on the impact strength and specific impact strength of PLA/iron composites was examined using FFF. Response surface methodology (RSM) was used to optimize the experimental design. The results revealed that POR had the most significant effect on the impact resistance data, while NT had the least effect. Reducing the POR led to improved impact resistance in the samples. Multi‐objective optimization results showed that the lowest NT (190°C), the lowest POR (30%), and a PS of 50 mm/s were the optimal conditions for multiple objectives. RSM was also utilized to develop mathematical models of impact properties, focusing on varying NT, POR, and PS, which can be used to predict desired impact properties.Highlights Nominal porosity has the most influence on the impact strength of PLA/iron composites. Optimum values were temperature of 190°C, nominal porosity of 30%, and speed of 50 mm/s. RSM was effective in enhancing the mechanical properties of composite materials. RSM models provide a predictive tool for future FFF‐printed composite parts. Maximum impact strength of 4.44 kJ/m2 was achieved.

Mechanical, thermogravimetric, and dynamic mechanical behavior of high-performance textile structural composite panels for automotive applications

The present study investigates the mechanical behavior of the textile structural composite (TSC) panels produced from different textile structures such as chopped fibre, unidirectional (UD), bidirectional (2D plain), and three-dimensional (3D) orthogonal woven structures using two different high-performance fibres (glass and basalt) for automotive components such as door and bonnet of a car. These composite specimens were manufactured by vacuum-assisted resin transfer molding (VARTM) process. Scanning electron microscope (SEM) analysis was carried out to evaluate morphological damage and fractography of fabricated composites. In addition, the thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA) of the TSC panels were also carried out. Basalt fibre reinforced textile structural composites (BFRTSC) exhibited higher specific tensile, flexural, and impact strength as compared to glass fibre reinforced textile structural composites (GFRTSC). The basalt UD preform reinforced composite panels show a ∼ 372 % increment in specific tensile strength, ∼ 436 % increment in specific flexural strength, and ∼ 818 % increment in specific impact strength as compared to the conventional metallic automotive components. The TGA and DMA confirmed that the developed BFRTSC panels are thermally stable and exhibited higher storage modulus compared to GFRTSC panels. The developed TSC panels are considered a potential candidate to replace traditional metallic counterparts in automotives.

Study on properties of BF/PP composites and plastic parts manufacturing by mold opening foaming injection molding

Basalt fiber (BF), as an emerging natural and environmental-friendly material, possesses a broad application prospect. Herein, lightweight and strong BF reinforced polypropylene (BF/PP) composite foams were successfully prepared using mold opening foam injection molding (MOFIM) technology. It was revealed that the combination of increased crystallinity and enhanced rheological behavior in turn contributes to the improved foaming behavior of 20%BF/PP, which reduces the cell size of PP to 36.38 μm and boosts the cell density by a factor of 2 under an expansion ratio of 1.2. The improvement effect of BF on cell structure is more obvious at higher expansion ratio. This fine and dense cell structure further augments the impact performance and flexural modulus of BF/PP composite foams. Compared to pure PP, 20%BF/PP composite foams experienced an increasement of impact performance, which is increased by 68.8% to 2.7 kJ/m2, and its flexural modulus also elevated significantly by 224.8% to 2440.25 GPa. Due to its excellent weight reduction effect, the specific impact strength and specific flexural modulus remain at much higher levels than those of PP foam. This indicates that BF and MOFIM technique successfully prepared a ductile material with excellent impact resistance, modulus and thermal insulation properties.

Investigation of impact resistance of grouting materials

Background: Cementing of the production column is an important stage of well completion, which in turn requires the correct selection of the formulation of grouting solutions that ensure the durability of well operation. Aim: In this article, the analysis of the main factors affecting the quality of well cementing at each stage is carried out, and the impact resistance of grouting materials in the bottom-hole zone of the well is considered in detail. Materials and methods: The method of assessing the impact resistance of grouting materials by the magnitude of impact strength is described. Results: The results of research work carried out on the basis of this method with reinforced grouting solutions used to increase the specific impact strength of cement stone are presented. Conclusion: Experimental studies have shown the effectiveness of polypropylene fiber and building micro-reinforcing fibers at concentrations of 0.25 and 0.5%.

Effect of Hollow Glass Microsphere (HGM) on Impact and Flexural Properties of High-Density Syntactic Foam Based Epoxy Composites

Syntactic foam composite offers versatile application possibilities in marine, structural, aerospace industries due to their good tensile, flexural, and compressive strength, corrosive resistance, high specific strength and modulus, light weight nature. Their porous structure is by mixing hollow particles called microspheres as fillers into matrix materials such as polymer, metal or ceramic etc. In this study, a high-density hollow glass microsphere is used to fabricate syntactic foam by mixing it with epoxy resin. Five different compositions 5, 10, 15, 20 and 25 vol% of hollow glass microspheres were varied in fabricating the syntactic foam. Impact and flexural properties were investigated on the syntactic foam. All the compositions of the volume fraction variations of hollow glass microsphere content in the syntactic foam increased more than the neat epoxy. The highest impact resistance, flexural strength and flexural modulus is at 5 vol%, 113.12 kJ/m2, 86.7 MPa, and 80 GPa respectively with 25.2%, 38.29%, and 33.25% increase respectively more the neat epoxy while the specific impact and flexural strength is at 25 vol% with 53.78% and 57.77% increase respectively more than the neat epoxy.

Polivinil klorür (PVC)’ün geri dönüştürülmesi: PVC köpük üretimi ve Karakterizasyonu

Plastikler hayatımızın birçok alanında yıllardır kullanılmakta olup kullanım ömrü sonunda önemli miktarda atık oluşturmaktadır. Doğada uzun yıllar bozunmadan kalan ve çevreye zarar veren bu malzemelerin geri dönüştürülüp tekrar kullanıma kazandırılması önem taşımaktadır. Termoplastik köpük malzemeler düşük yoğunluk, yüksek spesifik mukavemet, yüksek enerji absorblama özellikleri ve üstün yalıtım özelliklerinden dolayı ısı yalıtımı, otomotiv koltukları, ambalaj malzemeleri ve enerji absorblayıcı (soğurucu) malzemeler olarak yaygın bir şekilde kullanılmaktadır. Bu çalışmada, en çok kullanılan plastiklerden biri olan ve önemli miktarda atık oluşturan polivinil klorür (PVC)’ün geri dönüşüm yoluyla termoplastik köpük malzemelerin üretiminde kullanımı amaçlanmıştır. Bu amaçla kapı ve pencere profil atıklarından elde edilen atık PVC kullanılarak termoplastik köpük malzemeler üretilmiştir. PVC köpük malzemelerin bazı fiziksel, mekanik ve morfolojik özellikleri üzerine kimyasal köpük oluşturucu miktarının etkisi incelenmiştir. Üretilen PVC köpük malzemelerde kimyasal köpük oluşturucu malzeme miktarının artması ile PVC köpüklerin yoğunluk değerlerinde %40’lara kadar bir azalma sağlanmıştır. PVC köpüklerin spesifik darbe direnci değerleri kimyasal köpük oluşturucu miktarı ile doğrusal bir şekilde artış göstermiştir. Köpüklerin hücre yapısı incelendiğinde ise kimyasal köpük oluşturucu miktarının artması ile hücre birleşmelerinin meydana geldiği ve daha büyük hücrelerin oluştuğu gözlemlenmiştir.

Influence of Material Thickness on the Ductile Fracture of Steel Plates for Shipbuilding

Abstract In the shipbuilding industry, the risk of brittle fractures is relatively high because some units operate in arctic or subarctic zones and use high thickness (up to 100 mm) steel plates in their structures. This risk is limited by employing certified materials with a specific impact strength, determined using the Charpy method (for a given design temperature) and by exercising control over the welding processes (technology qualification, production supervision, and non-destructive tests). However, for offshore constructions, such requirements may prove insufficient. For this reason, regulations employed in constructing offshore structures require conducting crack tip opening displacement (CTOD) tests for steel and welded joints with thicknesses exceeding 40 mm for high tensile strength steel and 50 mm for other steel types. Since classification codes do not accept the results of CTOD tests conducted on specimens of sub-sized dimensions, the problem of theoretically modelling the steel construction destruction process is of key importance, as laboratory tests for notched elements of considerable thickness (100 mm and higher) are costly and problems stemming from high loads and a wide range of recorded parameters are not uncommon. The aim of this research is to find a relationship between material thickness and CTOD value, by establishing and verifying a numerical model that allows recalculating a result obtained on a sub-size specimen to a full- size specimen for a ductile fracture mode. This work presents results and conclusions from numerical modelling and compares them with laboratory test results of the elastic-plastic properties of high thickness steel, typically used in offshore applications.

Functionally graded lightweight cement-based composites with outstanding mechanical performances via additive manufacturing

Light weight and high strength are contradictory issues for most engineering materials. Through 3D concrete printing (3DCP), functionally graded construction materials can be produced to achieve material economization and outstanding mechanical performances simultaneously. In this paper, cement-based composites exhibiting lamellar microstructures with graded porosity and fiber distribution, were fabricated via depositing cement pastes with different densities and fiber contents at designed positions. Compared with casted homogeneous concrete, printed graded composites demonstrate 75%–92% higher specific bending strength and 2.2 times of specific impact strength. In addition, the specific compressive strength of several graded composites displays 76%–96% increasement when the pressure is parallel to the lamellar structure. Unique failure modes also appear in graded composites, including crack twisting, multiple cracking and compressive anisotropy. Finite element simulations reveal that a rational stress “redistribution” inside the graded composites, which follows the strength distribution of constituent materials, contributes to the superior mechanical performances under light weight for the graded architectures. This work paves a facile and valid way for the design and fabrication of functionally graded cement-based composites, as well as brings great potential and more insights into 3DCP technique.

ABOUT REQUIREMENTS TO PLUGGING MATERIALS AND TO TUBING TECHNOLOGY FOR THE CASING COLUMNS WORKING IN EXTREME CONDITIONS

The most vulnerable elements of the well lining is cement paste in injection wells and the lower parts of the intermediate and surface casings, which suggests the need for the study of additional requirements to plugging materials and lining technology of the specified lining elements. Analysis shows that the main number of workover happens for the share of injection wells, and the number of detected violations in injection wells which is more than an order of magnitude exceeds the corresponding figures for the production casing. Samples of cement stone, selected from the injection and production wells showed that in injection wells, the cement stone collapses in 4-5 years.The mechanism and kinetic process of destruction of cement stone under the influence of leaching was considered and the ways of increasing the durability of linings in injection wells were shown. Leaching corrosion processes in injection wells strengthens during the formation of cracks in the cement stone as a result of technological operation inside the casing string. The most dangerous technological operations are; perforation and deepening of the well. In order to obtain high-quality well anchoring, it is inevitable to regulate the basic properties of cement mortars with the help of various chemical reagents. At the same time, the filtration characteristics (water output and water separation), setting time, pumpability, rheological parameters, as well as the properties of the resulting stone require correction most often in grouting solutions It is shown that for plugging materials, the most preferred way to increase the resistance of grouting stone to dynamic loads is dispersed reinforcement, which can be effectively regulated by the most important characteristics of cement slurries and cement stone can be obtained from them. Studies have been conducted on the influence of basalt fiber and polyamide fiber on the basic physical and mechanical properties of the resulting stone, such as the strength of cement stone, deformation of cement stone during destruction, the specific impact strength of Portland cement stone, as well as the permeability of cement stone. Studies have shown positive results of the addition of basalt fiber at concentrations up to 2%.

A Stiffness-Switchable, Biomimetic Smart Material Enabled by Supramolecular Reconfiguration.

In nature, stiffness-changing behavior is essential for living organisms, which, however, is challenging to achieve in synthetic materials. Here, a stiffness-changing smart material, through developing interchangeable supramolecular configurations inspired from the dermis of the sea cucumber, which shows extreme, switchable mechanical properties, is reported. In the hydrated state, the material, possessing a stretched, double-stranded supramolecular network, showcases a soft-gel behavior with a low stiffness and high pliability. Upon the stimulation of ethanol to transform into the coiled supramolecular configuration, it self-adjusts to a hard state with nearly 500-times enhanced stiffness from 0.51to 243.6MPa, outstanding load-bearing capability (over 35000times its own weight), and excellent puncture/impact resistance with a specific impact strength of ≈116kJm-2 (gcm-3 )-1 (higher than some metals and alloys such as aluminum, and even comparable to the commercially available protective materials such as D3O and Kevlar). Moreover, this material demonstrates reconfiguration-dependent self-healing behavior and designable formability, holding great promise in advanced engineering fields that require both high-strength durability and good formability. This work may open up a new perspective for the development of self-regulating materials from supramolecular-scale configuration regulation.

First lamina hybridization of high performance CFRP with Kevlar fibers: Effect on impact behavior and nondestructive evaluation

The impact behavior of a carbon-Kevlar hybrid composite, widely used in sport car manufacturing, was evaluated. To highlight the hybridization effect, comparative analyses were performed with the basic CFRP laminate having the same lay-up. Tensile, bending and low velocity impact tests, followed by nondestructive inspections, highlighted that Kevlar first lamina hybridization leads to an increment in specific impact strength, up to 55%. To assess the most reliable technique to detect the impact damage, nondestructive evaluation was performed by pulsed thermography, phased array ultrasonic technique, computed tomography and digital radiography. Phased array ultrasonic technique can be considered the most appropriate technique.

Mechanical and Rheological Properties of Bamboo Pulp Fiber Reinforced High Density Polyethylene Composites: Influence of Nano CaCO3 Treatment and Manufacturing Process with Different Pressure Ratings

In order to investigate the effect of the relative motion of nano CaCO3 reinforced bamboo pulp fiber (BPF)/HDPE composite components on the mechanical performance, a comparative study was performed. BPF was treated by nano CaCO3 blending (BM) and impregnation modification (IM) technology. The composites were produced using hot press (HPMP), extrusion (EMP) and injection molding process (IMP). The physical morphology of BPF was similar at different manufacturing processes. Compared to the samples manufactured by HPMP, a decrease in the (specific) flexural strength of BPF/HDPE composites and an increase in those of composites treated by nano CaCO3 manufactured by EMP and IMP were observed. The injection molded composites exhibited the best values in the (specific) impact strength, (specific) tensile properties. IM had a greater effect on the rheological behavior of the composites than BM, and nano CaCO3 treatment most effectively affected the performance of the extrusion molded composites.

INFLUENCE OF DILUENTS AND PLASTICIZERS ON THE PROPERTIES OF EPOXY-POLYSULFIDE COMPOSITES

It was found that to increase the adhesive and physicomechanical properties of compositions based on epoxy resin and polysulfide rubber (thiokol), cured without heat treatment, it is necessary to carry out a preliminary thioetherification reaction (PRTE) due to the interaction of rubber mercaptan groups and oxirane cycles of epoxy resin at elevated temperatures and then use the product of this reaction to cure at room temperature. Composite materials based on the products of the thioetherification reaction significantly surpass analogs based on mechanical mixtures of epoxy resin and thiokol in terms of cohesive and adhesive strength, deformation capacity, fracture work, and specific impact strength. It is shown that the introduction of both diluents and plasticizers into the products of the preliminary thioetherification reaction of epoxy resins and polysulfide rubbers leads to an increase in the parameters of tensile strength and deformation capacity. The greatest strengthening effect is achieved with the use of oligoesteracrylate MGF-9 and glycidyl ether of diethylene glycol DEG-1, the smallest - with the introduction of the plasticizer EDOS. It was found that the introduction of plasticizers promotes some increase in the adhesive strength, but much less in comparison with the cohesive strength. In this case, the adhesion and cohesive characteristics change antibatically. It has been shown by dynamic mechanical spectrometry that the presence of diluents and plasticizers in epoxy-polysulfide composites leads to a decrease in the temperatures of the maximum values of the tangent of the angle of mechanical losses, loss modulus, the initial and final sections of the transition of the material from the glassy to the highly elastic state, as well as the density of the chemical network in the epoxy matrix.