Hashin Damage Criteria Research Articles

Investigation of Low Velocity Impact Behavior of Aluminum Honeycomb Sandwich Structures with GFRP Face Sheets by Finite Element Method

The aim of this study is to examine the low velocity impact behavior of aluminum honeycomb sandwich structures with glass fiber reinforced plastic (GFRP) face sheets with the help of finite element method. In the study, low velocity impact tests were carried out in the LS DYNA finite element program to examine the effects of face sheets thickness, core number, wall thickness, impact location and impact velocity on maximum contact force, absorbed energy efficiency and damage mode. Progressive damage analysis based on the Hashin damage criterion and the combination of Cohesive Zone Model (CZM) and the bilinear traction-separation law was performed using the MAT-54 material model. At the end of the study, it was determined that the face sheets thickness in sandwich structures had a significant effect on the impact resistance up to a certain impact energy. It has been observed that as the impact velocity gradually increases, there is a decrease in the contact force after a certain threshold value. As the impactor velocity increases, the energy absorption efficiency also increases. It has been determined that the location of the impact is very effective on peak force and energy absorption efficiency. The effect of the number of core layers depends on the face sheets thickness. When the face sheets thickness was not damaged at first contact, the peak force value increased in parallel with the number of layers. It was determined that the dominant damage mode after impact was matrix damage. It has been observed that as the energy level of the impactor increases, damage also occurs on the back surfaces.

Numerical Investigation of the Effects of Impactor Geometry on Impact Behavior of Sandwich Structures

The aim of this study is to examine the impact performance and damage behavior of sandwich composite structures with a core material of aluminum and a facesheet of glass fiber composites using the finite element method. In the study, the effects of impactor shape, impact velocity and number of core layers on peak force, absorbed energy efficiency, maximum displacement and damage deformation were examined. For low velocity impact simulation, progressive damage analysis was performed based on the Hashin damage criterion using the MAT 54 material model in the LS DYNA finite element program. While providing the connection between the core structure and its surfaces, a Cohesive Zone Model (CZM) based on the bilinear traction-separation law was created and examined. At the end of the study, it was determined that the shape of the impactor had a significant effect on impact resistance. Energy absorption efficiency may vary as impact energy changes. However, as the impact energy increases, the energy absorption efficiency increases. It was determined that the largest and dominant damage type for all three impactors was matrix damage.

Effect of geometric configurations and curvature angle of corrugated sandwich structures on impact behavior

AbstractThe aim of this study is to numerically investigate the low‐velocity impact behavior of carbon fiber reinforced orthogonal woven fabric composite sandwich structures with five different geometric configurations and four different curve angles. Low velocity impact simulations were performed in LS DYNA finite element program to investigate the effects of core configuration and curve angle on peak contact force, energy absorption efficiency and damage mode. A progressive damage analysis based on the combination of the Hashin damage criterion and the Cohesive Zone Model (CZM) with bilinear traction‐separation law was performed using the MAT‐54 (ENHANCED_COMPOSITE_DAMAGE) material model. Among the five different cores, Trapezoidal core has the highest peak force average of 2.9 kN while Triangular core sandwich structure has the lowest with 1.23 kN. Absorbed energy efficiency average was highest for rectangular core with 0.95 and lowest for sinusoidal core with 0.69. The specific absorbed energy value was highest for Triangular core with 0.312 J/g and lowest for Sinusoidal core with 0.178 J/g. The damage area on the structure increased with increasing curve angle. It was determined that the core structure and curve angle is an effective parameter on peak force and energy absorption efficiency.Highlights Impact behavior of sandwich composite structures was examined. The effects of core type and curve angles on peak force, energy absorption efficiency and specific absorption energy were investigated. Specific absorption energy rates were compared with studies in the literature.

Low‐velocity impact resistance of the Z‐pin reinforced carbon fiber composite laminates

AbstractA voronoi user material subroutine (VUMAT) was developed using the three‐dimensional Hashin damage criterion and exponential nonlinear damage evolution method. An interlayer damage model based on the quadratic nominal stress (QUADS) criterion and B‐K fracture criterion was introduced, and a finite element model of Z‐pin reinforced composite laminates under low‐velocity impact was established. The low‐velocity impact behavior of Z‐pin reinforced composite laminates with different impact velocities (0.6 m/s, 0.4 m/s, and 0.3 m/s), different layup forms ([0°/90°]4 and [0°/45°/90°/−45°]2), and different Z‐pin spacing (4 mm, 8 mm, and 16 mm) was studied using ABAQUS. The results indicate that different layup forms have little effect on the low‐velocity impact behavior of Z‐pin reinforced composite laminates. The Z‐pin spacing has a significant influence on the low‐velocity impact behavior of Z‐pin reinforced composite laminates. When the impact velocity is 0.4 m/s, the specific energy absorption of composite laminates with Z‐pin spacing of 16 mm is 85.93% and 87.7% lower than that of composite laminates with Z‐pin spacing of 4 mm and 8 mm. As the Z‐pin spacing decreases (Z‐pin density increases), the impact resistance of Z‐pin reinforced composite laminates first increases and then decreases.Highlights• The low‐velocity impact of Z‐pin reinforced composite laminates was studied.• Analyzed the effect of layup forms of laminates on their impact behavior.• Explored the influence mechanism of Z‐pin spacing on the impact behavior.• Studied the energy absorption of different Z‐pin spacing under impact velocity.

CFRP-strengthened shear walls: Combined effects of CFRP and reinforcement ratio

This study presents a three-dimensional numerical model based on the Hashin damage criteria to assess the seismic performance of Carbon Fiber Reinforced Polymer (CFRP)-strengthened Reinforced Concrete (RC) shear walls, accurately capturing the rupture of CFRP strips. The effectiveness of various CFRP-concrete interface modeling methods in capturing CFRP debonding was initially discussed. A series of numerical simulations were then conducted to investigate the combined effects of the CFRP ratio and the horizontal reinforcement ratio on the seismic behavior of CFRP-strengthened shear walls. The results indicate that an increase in the CFRP ratio reduces the failure degree of shear walls, as the shear damage shifts progressively from the concrete and horizontal reinforcement to the CFRP strips. However, an increase in the horizontal reinforcement ratio counterproductively weakens the shear-strengthening effect provided by the CFRP strips. To specifically evaluate the shear contribution of the CFRP strips, a novel coefficient was proposed and validated, capturing the combined effect of the CFRP ratio and the horizontal reinforcement ratio on the shear contribution of the CFRP strips. This coefficient provides a quantitative measure to optimize the reinforcement design of RC shear walls.

Numerical Investigation of the Effect of Deltoid Radius on Tensile Load in T-joints

In this study, T-shaped joints were designed from composites with different deltoid radius. For this purpose, carbon fiber woven fabrics were preferred as reinforcement elements. Then, tensile analyzes were performed on these composite T-joints. The effect of the deltoid radius on the maximum tensile load and damage behavior of the structure was examined. As a result of the analyses, fiber tensile-compression damage images occurring in the structure for each deltoid radius were obtained along with the load-displacement graph. The Hashin damage criterion was preferred for damage onset. Material Property Degradation (MPDG) method was used for damage progression in progressive damage analysis. By increasing the deltoid radius from 6 mm to 12 mm, the maximum contact load increased by approximately 10%, and by increasing it to 18 mm, the maximum contact load increased by approximately 20.11%. Fiber compression damage, spread over a wide area on the lower surface of the flange where it does not come into contact with the web, was determined to be the dominant damage type, and it was determined that this damage decreased with the increase of the deltoid radius. it was observed that as the deltoid radius increases, the T-jointed composite structure exhibits more rigid material behavior.

Effect of bondline thickness on the mechanical performance of CFRP laminate with asymmetric damage repaired by double-sided adhesive patch

As a common CFRP repair method, double-sided adhesive patch has been widely used in the automotive and aeronautic industry. More specific research is thus needed to help better understanding the effect of repairing parameters on the mechanical performance of CFRP structures after patch bonding. In this paper, experimental and Finite Element Modelling (FEM) efforts were made on the adhesive repaired CFRP laminate with different bondline thicknesses. Artificial damage was prefabricated in the centre of the CFRP laminate, which was then repaired through double-sided adhesive patch. Quasi-static tensile tests were conducted on the repaired specimen up to failure, to obtain the load-displacement curves. With a bondline thickness of 0.5 mm, the repaired CFRP structure reached its maximum peak load, increased by 25.3% and 26.4% compared to 0.2 mm and 1.0 mm bondline thicknesses, respectively. SEM observations were used to analyse the influence of adhesive thickness on the fracture modes. Combined with Cohesive Zone Model (CZM) for the adhesive layer and Hashin damage criterion for the CFRP, the FE model of the CFRP laminate repaired with double-sided adhesive patch subjected to tensile loading was established. Finally, the damage evolution as well as the failure modes in the parent laminate and adhesive layer with different bondline thicknesses were compared and analysed. It was revealed that bondline thickness can effectively affect the mechanical performance of CFRP laminate after adhesive patch repair.

Experimental study on axial compression behavior of square pultruded GFRP tubular stub column

To investigate the influence of aspect ratio and width-to-thickness ratio on the axial compression behavior of square pultruded glass fiber-reinforced polymer (GFRP) tubular stub columns, axial compression tests were conducted on 12 GFRP tubular columns. The mechanical properties of the GFRP tubular columns, including load-bearing capacity, initial stiffness, compressive toughness, and ductility coefficient, were analyzed. The test results reveal that all GFRP tubular columns exhibit crushing failure, with specific failure modes, including mid-section fracture and longitudinal tearing along the corners of the columns. The load-bearing capacity is negatively correlated with the aspect ratio and width-to-thickness ratio. The initial stiffness negatively correlates with the aspect ratio, and the compressive toughness negatively correlates with the width-to-thickness ratio. The Hashin damage criteria for the C3D8R solid element was developed by utilizing the explicit finite element subroutine ABAQUS-VUMAT to analyze the axial compression behavior of GFRP tubular columns. Through parameter analysis, the relationship between the load-bearing capacity and fiber orientation was obtained, and an empirical equation for predicting the load-bearing capacity of the GFRP tubular column was proposed.

Comparison of Hashin and Puck criterions for failure behavior of pin loaded composite plates

AbstractIn this study, the failure behavior of carbon fiber‐reinforced pin‐jointed composite plates were analyzed for different criteria. For this purpose, composite plates with a single and double pin joints were prepared from four layers carbon fiber composites. The effect of pin number, pin position on plate damage load and type was investigated experimentally and numerically under the tensile test. Numerically, progressive damage analysis was performed using Hashin and Puck failure criteria, and the approach rates to the experimental results were determined. It was observed that the experimental results obtained for single pin joint composites and the numerical data obtained using the Puck damage criterion were at least 87 % compatible, and this rate was determined as 85 % for the Hashin failure criterion. For the double pin jointed composites, it was seen that the experimental results and the results of the Puck damage criterion were compatible with at least 90 %, and this rate was obtained as 84 % for the Hashin failure criterion. The dominant damage type seen in the specimen is matrix shear and fiber compression according to the Hashin damage criterion, inter fiber failure in transverse tension for Puck.

Experimental and numerical investigation of patch effect on the bending behavior for hat-shaped carbon fiber composite beams

Abstract In this study, reinforced composite panels with hat-shaped profile were produced from woven carbon fiber fabrics by vacuum infusion method. Holes were drilled on the crown surface of these panels and repaired with composite patches. The mechanical behavior was examined by performing a three-point bending test on the obtained patched and unpatched specimens. The contribution of the repair to the failure load of the damaged specimens under bending load has been clearly determined. In the numerical part, Hashin damage criterion was used for the beginning of damage. For damage progression, both Continuum Damage Mechanics and Material Property Degradation methods were preferred and compared. In the analysis carried out using the finite element package program Workbench, the cohesive zone model (CZM) was added to the model and its effect on the damage behavior and load of the composite structure was determined. As a result of the experiments and analyses, it was seen that the maximum contact force of the specimens under the bending load decreased by 29.8 % by increasing the number of holes on the specimen surface from 1 to 3. The maximum contact force was determined to increase by 18.52 % due to repairing the three-hole specimens with a patch.

Failure of 3D-printed composite continuous carbon fibre hexagonal frames

This study presents an approach to enhancing and expanding the structural performance of composite materials by tailoring their geometry. We explored the potential of continuous carbon fibre composite additive printing to create complaint frames based on hexagonal cell design with the aim to better understand and control their mechanical performance. Our investigation examines the failure behaviour of these frames under remote tensile loading. By experimenting with various geometries and aspect ratios at the frame sites, we gained insight into different failure loads and modes. To predict these results, we developed a computational model based on multiscale homogenisation and the Hashin damage criterion, which showed a high degree of precision compared to our experimental results. The findings validate the effectiveness of our computational model, but also highlight the practical applications of additive manufacturing of composites. This research aims to contribute to the advancement of structural design and material optimisation by engineering of composite materials for specific applications, emphasising the integration of their intrinsic strength and lightweight properties with material efficiency and compliance achieved through geometric design considerations.

FE Analysis on Size Effect in Torsional Behavior of Rectangular RC Beams with and Without FRP Strengthening

Although torsion is usually considered a secondary consideration in structural design, it can lead to failures, especially in structures with irregular geometry exposed to seismic forces or in unique situations. While some studies have explored the size effect on the torsional behavior of RC beams, none have addressed the impact of reinforcement. This paper investigates the size effect on the torsional behavior of RC beams with varying reinforcement ratios, including both FRP sheets and steel rebars. In this study, the torsional behavior of reinforced concrete (RC) beams with and without FRP strengthening was investigated numerically. Modeling was carried out by Finite element (FE) software ABAQUS and validated using experimental data from literature. The torsional behavior of 24 models with differences in cross-section size and reinforcement ratio were investigated. Concrete damage plasticity, Hashin damage criteria, and von Mises stress were used to investigate the damage in concrete, FRP, and steel, respectively. The cracking torsional moment, ultimate torsional moment, and torque-twist curve of the beams were evaluated and presented. The results indicated the presence of a significant size effect in the torsional strength of beams. After reinforcing the beams with FRP fabrics, the average cracking moment increased by a range of 1.72% to 36% across different groups of beams. An 8.2% increase in ultimate strength is observed with just a 0.4% rise in the FRP strengthening ratio. Post-cracking behavior was seen in 8 models with adequate steel and FRP reinforcement ratio.

Manufacturing and mechanical properties of adjustable stiffness hierarchical orthogrid stiffened cylinders

AbstractModular spacecraft offer promising prospects in the aerospace industry due to their ability to adapt to complex missions and diverse space environments. Nevertheless, such spacecraft may face load‐bearing structure adaptation issues caused by the changes in load demand when replacing sub‐modules for various missions. This necessitates the re‐design and manufacturing of load‐bearing structures, resulting in significant increases in product cycles and costs. To overcome this challenge, innovative composite hierarchical orthogrid stiffened cylinders (CHOSCs) which offer adjustable stiffness and strength to suit various mission requirements are proposed. To investigate the stiffness and strength adjustability, high‐precision composite orthogrid stiffened cylinder (COSC), CHOSC with three primary ribs (T‐CHOSC), and CHOSC with four primary ribs (F‐CHOSC) were manufactured and tested. The results demonstrate that CHOSCs exhibit stiffness and strength adjustability and significantly improve the cylinder's load‐bearing efficiency. Furthermore, a finite element model based on the Hashin damage criterion was employed to capture the end failure of the primary ribs and the local basic rib fractures near the cylinder end. CHOSCs present a feasible solution to the load‐bearing structure adaptation issues caused by the changes in load demand when replacing sub‐modules for various missions and hold significant potential for advancing the aerospace industry.Highlights Composite hierarchical orthogrid stiffened cylinders (CHOSCs) are proposed. High‐precision CHOSCs are manufactured by combined metal molds. Load‐bearing capacity and failure behavior are investigated. CHOSCs exhibit stiffness adjustability and load‐bearing efficiency. CHOSCs could solve the structure adaptation issues in modular spacecraft.

Numerical study of the influence of layers number and their orientation in a CFRP using improved ANN based on Enhanced Jaya

The advancement of technology in the field of artificial intelligence has facilitated significant progress in various areas, particularly in optimizing the structural configuration of multilayer composites. This study's primary objective is to investigate how geometric parameters, such as fiber orientation and the number of layers influence the mechanical properties of these materials. To predict fracture toughness in bending tests, we employed a hybrid optimization technique (E-Jaya-ANN) and compared it with the Jaya-ANN method to assess the improved approach's accuracy. Furthermore, we developed a numerical model based on the Hashin damage criterion using ABAQUS software to anticipate the response of composite specimens (CFRP) when subjected to a bending load. We validated the reliability of the code results by comparing them with experimental data. Subsequently, we generated a series of numerical results, representing various practical scenarios, to serve as the foundation for training an artificial neural network (ANN). This enabled us to obtain an enhanced architecture for the laminate layers.

Experimental study and finite element analysis on axial compression performance of CFRP-PVC confined coral seawater and sea-sand concrete columns

In this paper, a composite column using carbon fibre reinforced plastics and polyvinyl chloride composite tube (CFRP-PVC) to constrain coral aggregate seawater sea-sand concrete (CSSC) was proposed, and CFRP was pasted on the inner and outer walls of the PVC tube. To investigate the effects of the number of CFRP layers and void defects on the axial compression performance of PVC tubes, six specimens were made for axial compression loading tests and finite element parameter analysis. The results indicate that due to PVC improving the integrity of CFRP, PVC tube provide a stress transfer path for CFRP, placing CSSC in a triaxial compression state. When both the inner and outer walls of the tube are pasted with CFRP, brittle failure of CFRP-PVC tube can be effectively avoided and have relatively superior mechanical properties. In the same situation, when one layer of CFRP is pasted on the inner wall of the tube, it has better ductility and bearing capacity. When two layers of CFRP are pasted on the outer wall of the tube, the coefficient of constraint stress increase is as high as 121.5%, and the void defect only has a significant impact on ductility. A finite element model of CFRP-PVC confined CSSC columns considering Hashin damage criterion was established based on ABAQUS, accurately predicting the failure process and CFRP damage morphology of test columns under axial load. Parameter analysis shows that when the confinement coefficient of CFRP-PVC confined CSSC columns is less than 0.3 and the height-diameter ratio is greater than 15, the load-displacement curve will lose the strengthening stage, and increasing the number of outer CFRP layers will slightly increase the stiffness of the strengthening stage. A bearing capacity calculation method suitable for CFRP-PVC confined CSSC was proposed based on the model of steel tube confined concrete, with an error of 1.2%.

Evaluation of the low-velocity impact response of high-performance multi-axial warp-knitted flexible composites

This article aims to investigate the dynamic behavior of high-performance multi-axial warp-knitted flexible composite materials under low-velocity impact tests through experiments and numerical simulations. In this paper, high-performance multi-axial warp-knitted flexible composites were prepared. Three different preparation processes, 175°C-5 min, 185°C-10 min, and 195°C-15 min, were designed for the multi-axial warp-knitted flexible composites. Studied the impact response of different preparation processes, initial impact energy, and punch shapes and diameters on materials. The results showed that the flexible composites prepared by various processes exhibit the same impact response curves in the impact resistance process, while the damage morphology and failure modes of the samples are different. Different initial impact energies caused multiple failure modes in the samples. The material showed penetration damage at high energy impacts and permanent depression damage at low energies. For different punch shapes, the impact resistance of materials to hemispherical punches is better than that of cylindrical punches. Numerical simulations were carried out using the finite element software ABAQUS. The custom material subroutine (VUMAT) based on the Hashin damage criterion model was implemented in the finite element program. The experimental and numerical simulation results agree regarding impact response characteristics. This paper analyzes the composite damage shapes, crack extensions caused by low-velocity impact tests and finite element simulation on multi-axial warp-knitted flexible composites. It provides a valuable reference for failure and structural optimization of multi-axial warp-knitted flexible composites for architectural applications.

The Effect of Core Metal Layer Thickness on the Behavior of Carall Under Low Velocity Impact Loading

Fiber metal laminates are the advanced composite materials, in which the metal and FRP layers are stacked alternatively to achieve the desired properties. The presence of FRP layers enhances the fatigue, fracture properties and weight savings. Durability and plasticity of the metal plays a significant role in the design of fiber metal laminates. This study evaluates the role of middle metal layer (core) thickness on the behavior of Carall fiber metal laminates under low velocity impact loading. Two types of Carall 3/2 with middle layer of varying thickness are considered. The metal volume fraction is same for both the laminates. Finite element simulations have been carried out for the laminates considered according to the standard ASTM D7136. Johnson–cook plasticity and damage model and two-dimensional Hashin damage criteria have been used to model the aluminum and CFRP respectively. From the study, it was found that the placement of thicker layer at the middle position in the Fiber metal laminate enhances the impact resistance of Carall. The energy absorption studies also indicate that the presence of thicker layer at the middle position increases the energy absorption capability.

Effect of Contact Interaction Conditions on Impact Simulation Results of CFRP Laminate

Finite element based contact impact analysis is an important tool to design composite structures for ballistic impact applications. In the current study, a user-defined material subroutine (VUMAT) that supports 3D solid elements based on Hashin damage criteria for fiber and Puck damage criteria for matrix failure is used for numerical impact analysis. Impact on carbon fiber reinforced laminate (CFRP) of 3.6 mm thickness with [0,90,0]3s stacking configuration is carried out both in Abaqus/Explicit and Ansys/Explicit. The impact simulations are carried out to check the effectiveness of different contact interaction conditions to simulate projectile impact problems. The residual velocities of the projectile from the numerical simulations are compared with experimental results from the literature [1]. The contact interaction condition that gives residual velocities close to experimentally observed residual velocities is evaluated under three initial conditions. The simulations are also carried out in Ansys/Explicit to compare the effectiveness of simulating the same impact problem.

Safety assessment of underground steel pipelines with CFRP protection against subsurface blast loading

Underground steel pipelines are one of the most important mediums for transport of water, oil, natural gas and other hazardous or highly toxic gases. Its assessment against blast has become very crucial due to intentional and accidental explosions in the route of buried pipelines. In present study, evaluation of X70 grade steel pipelines against subsurface blasts is carried out numerically. A computational model with finite element technique is developed by implementing Coupled Eulerian-Lagrangian method in ABAQUS. A protective covering of Carbon Fiber Reinforced Polymer has been introduced to alleviate the impact of blast waves. The Jones-Wilkins-Lee, ideal gas Equation of State (EoS), Mohr-Coulomb plasticity criteria, are used to model the behaviour of explosive substances, air, and soil respectively. Hashin damage criteria and Johnson-Cook model are employed to assess the response of CFRP blanket and steel pipe, respectively. The Finite Element (FE) results were validated with available experiments and empirical formulae. The influence of different factors namely thicknesses of pipe, internal pressure, explosive charges, type of soil, and thickness of CFRP on performance of pipes against blast load are analysed and mitigation provided by protective covering is determined. The maximum decrease in strain was found to be 69.2% and 67.4% in the 14.6 mm and 26.2 mm thick steel pipe covered with 10 mm thick CFRP sheet, respectively. The maximum reduction in peak displacement values was found to be 36% and 55% for 14.6- and 26.2-mm thick pipes respectively. Also, safety criteria/zone for underground pipeline against subsurface blast loading is proposed. The present work could be helpful for blast resistant design of underground steel pipelines.

Effect of nonlinear material behavior on progressive failure analysis of pin-joint composites

In this study, the mechanical performances of glass fiber-reinforced notched and pin-connected composite plates were investigated experimentally and numerically. For this purpose, composite plates with a circular hole, semicircular double-edge notched, U-edge notched, and single and double pin joints were prepared from layer glass fiber composites. Tensile tests were carried out on the obtained specimens. The effect of notch type, number of pins, and position of pins on plate damage load and type was investigated for linear and non-linear material behavior. Progressive failure analysis was performed using the Hashin damage criteria. Subprogram codes were written in the Ansys program using the finite element method. According to the obtained data, it was determined that the type of notch and the number of pins have a significant effect on the damage loads of the plates and the behavior of the material is important in terms of convergence to the experimental results in numerical solutions. In single-pin composites, the type of damage changed from net-tension to shear out as the pin approached the free edge of the plate. It was observed that the distance between the pins did not have any effect on the damage type of the composites in the double-pin joint structure. Compared to single-pin joint composites, double-pin joint composites were found to carry a maximum of 34% more damage load. The convergence rate of experimental and numerical data was obtained as a minimum of 92.1% for nonlinear material behavior and a minimum of 73.4% for linear material behavior