Glass Fiber Content Research Articles

Prediction of the Shear Strength of Glass Fiber-Reinforced Clay Soil by Adaptive Neuro-Fuzzy Inference System (ANFIS)

In recent years, the use of artificial intelligence algorithms in geotechnical engineering has increased, and successful results have been obtained in geotechnical engineering using artificial intelligence algorithms. The objective of this study is to estimate the shear strength of glass fiber reinforced clay soil using ANFIS. For this purpose, specimens with different water contents (13%, 15% and 17%) and different glass fiber addition ratios (0%, 1%, 1.5% and 2%) were prepared. The ANFIS models were created using the shear strength (τ) data obtained by direct shear tests on the prepared specimens. To create the best fitting ANFIS model in the current study, 75%, 77%, 80%, and 83% of the data for training and 25%, 23%, 20%, and 17% of the data for testing were used, respectively. However, to estimate the shear strength in each ANFIS model, the normal stress (σ), glass fiber content (Fc), and water content (ω) are considered as input parameters. Statistical parameters such as root mean square error (RMSE), regression coefficient (R2), root square error (RSE), and mean absolute error (MAE) were also calculated to determine the success rates of the ANFIS models. Examination of the statistical parameters revealed that the data used 80% for training and 20% for testing provided the best results in estimating the shear strength of the ANFIS model.

Experimental Evaluation and Neural Network Prediction of Fatigue Life of E-Glass Fiber Reinforced Hybrid Composite Material

The present study focuses on investigating the impact of hybrid composite content and loading parameters on the fatigue life of E-glass fiber-reinforced composite. A mathematical model of the fatigue life was developed based on experimentation and expressed as a function of the composite content (Epoxy content (80%, 60%) wt., Novolac content (20%, 40%) wt., E-Fiber Glass content (10%, 20%, and 30%) wt.), and different loads using Adaptive Neural Fuzzy Inference Systems (ANFIS). In order to validate the ANFIS model, 30 fatigue cycle experiments were conducted. Using the experimental data sets, the ANFIS was trained with a momentum algorithm and an average absolute percentage error of 6.045% was obtained and compared to the output of the conventional Artificial Neural Network (ANN) Model. The testing accuracy was then verified with 6 extra experimental data sets and the average predicting error was 5.18%. the predicted ANFIS output data were then used to discuss the effect of the composite content and loading parameters on the fatigue life. The number and shapes of cracks observed on the failed specimens were analyzed under an optical microscope. The analysis revealed that the loading impact showed the highest influence on fatigue life for all types of enforcement and the sequence of strength was E- glass fiber, epoxy, and Novolac contents, respectively.

Microstructure and performance of glass fiber metal composite-bonded diamond segment with Cu-Sn-Ti alloy

To develop metal-bonded diamond tools without dressing during machining, a novel glass fiber metal composite bonding agent with Cu–Sn–Ti alloy was proposed. The three-point bending strength of the diamond segments and the Vickers microhardness of the solidified composite bonding agents were tested. The microstructures of the diamond segments were investigated and the wear tests were performed for each group of diamond segments. The results showed that diamond segments with glass fiber content of 1.55 wt % - 6.89 wt % exhibited lower bending strength (declined by 36.4%–80.4%) and smaller microhardness (reduced by 16.0%–87.9%), compared to those of the diamond segment with no glass fiber addition. Good bonds were formed among the Cu–Sn–Ti alloy, glass fibers, and diamond grits. Chemical reactions occurred between the Cu–Sn–Ti alloy and glass fibers during high-temperature brazing, forming new intermetallic compounds such as Ti5Si3, Ti2O3, and Ti(Cu, Al)2, which improved the bonding strength. With an increase in the glass fiber content, fractures were more likely to occur in the glass fibers than in the diamonds, resulting in the bending strength decreasing more and more slowly. The wear resistance of the diamond segments decreased gradually with increasing glass fibers weight content. The diamond segment with 4.98 wt % glass fibers exhibited the best and most stable wear performance.

Study on Strength Parameters on Fibers Using M30 Concrete

Abstract: This project work is associate degree experimental investigation on the influence of polyester and glass fibers on mechanical properties of the concrete employed in Construction. during this study 2 varieties of concrete mixes were ready one by one. polyester of 1% to 4% and Glass fiber of 1% to 3% by weight of cement were further to the mixes. A comparative analysis has been allotted for typical concrete with regard to the fiber strengthened in regard to their Compressive, Spilt tensile and Flexural Strength properties. because the Fiber content will increase Compressive, spilt tensile and Flexural Strengths area unit proportionately increasing. it's discovered that fibers multiplied on the far side 3% polyester and 2% glass fiber content leads to decrease in strengths. Economic analysis is indicating that with the addition of polyester and glass fibers will increase in economy results in higher initial value by eight to Martinmas is balanced by the reduction in maintenance and rehabilitation operations by using Fiber concrete as compared thereto of typical Concrete.

Improvement of mechanical and wear resistance property by varying glass fiber contents and amino-silicate coupling agents on polyamide 612 composites

Among the polyamide series polymer materials, PA612 has excellent mechanical properties and low moisture absorption characteristics. This work studied the effect of coupling agent addition on the crystallization behavior, adhesive wear, mechanical, thermal, and morphological attributes of glass fiber (GF) reinforced PA612 composites. Amino-silane was applied as a coupling agent to enhance the interfacial adhesion between glass fiber and the PA612 matrix. The loading level of the coupling agent was changed to 0.5, 1.0, and 2.0wt%, while the GF loading level in the composite material was 10, 15, 20, and 30wt%. The composite materials were analyzed via X-ray diffraction, tribological characterization, and adhesion wear test. The mechanical, rheological, and thermal properties were also investigated. In addition, scanning electron microscopy (SEM) analysis was used to study the analytical samples’ wear and fracture surfaces. Test results unveiled that adding 1.0wt% amino-silane coupling agent upgraded the fiber-matrix adhesion, mechanical properties (tensile strength:136 MPa), and corresponding wear resistance of GF reinforced PA612-based composites. Furthermore, it is compatible with pure PA612 substrates and has similar processing rheological behavior. These results reveal that the compiled PA612 matrix is highly viable for tribological applications comprising automotive parts, bearings, and bearing materials for space applications.

Study on the Mechanical Properties, Wear Resistance and Microstructure of Hybrid Fiber-Reinforced Mortar Containing High Volume of Industrial Solid Waste Mineral Admixture.

The use of a high volume of industrial solid waste mineral admixture and hybrid fiber can greatly reduce the amount of cement in mortar or concrete, improve its performance, ensure the service properties of mortar or concrete, and reuse industrial solid waste to reduce the environmental burden, which has significant research significance. In this paper, the mechanical properties, wear resistance and microstructure of hybrid fiber-reinforced mortar (HFRM) with a high content of industrial solid waste mineral admixture were systematically studied under different water/binder ratios. Mineral admixtures include fly ash, silica fume and granulated blast furnace slag (slag). The total content of hybrid glass fiber (GF) and polypropylene fiber (PPF) was 2% by volume fractions, and six different water/binder ratios ranging from 0.27 to 0.62 were used. The following conclusions were drawn: fibers have a significant negative effect on the properties of mortars with a low water/binder ratio (w/b = 0.27) and high content of mineral admixtures. In general, the effect of adding hybrid fiber on improving the wear resistance of mortar is more obvious. The average residual weight of hybrid fiber-reinforced mortar is the highest after the wear resistance test. Comprehensively considering the compressive strength, flexural strength, wear resistance and microstructure of the mortar samples, G8PP2-0.40 is the optimal mix ratio. At this time, the replacement rates of fly ash, silica fume and slag are: 20%, 5% and 30%, the water/binder ratio is 0.40, and the content of GF and PPF is 1.6% and 0.4%, respectively.

Application of Artificial Intelligence Models to Predict the Tensile Strength of Glass Fiber-Modified Cemented Backfill Materials during the Mine Backfill Process

Cemented backfill coal mining technology is gradually becoming a key technology for green mining of coal resources. And cemented backfill materials generally have congenital defects such as poor crack resistance, poor durability, and high brittleness, which restrict the promotion and application of cemented backfill coal mining technology. Due to the complex stress environment of in situ stress, mining stress, water pressure, and gas pressure, cemented backfill materials need to have good mechanical properties, and glass fiber is usually used to mix into cemented backfill materials to improve its performance, but there are many problems including complex testing process, high cost, and long time-consuming in the study of mechanical properties of glass fiber-modified cemented backfill materials (GFCBM) by laboratory tests. Consequently, this study proposed and compared four artificial intelligence models to forecast the tensile strength of GFCBM. Firstly, the laboratory tests of tensile properties of GFCBM under different influence factors were implemented to supply the prediction model with dataset. The input variables are aeolian sand content, cement content, glass fiber length, and glass fiber content, and the output variable is the tensile strength of GFCBM. The correlation coefficient ( R ), mean absolute error (MAE), and root mean square error (RMSE) are selected to assess the estimated performance of the hybrid intelligent model. The results indicate that the four hybrid artificial intelligence models show a latent capacity for forecasting the tensile strength of GFCBM, and according to the order from high to low, the prediction ability of the four prediction models is as follows: ABC-SVM, GA-SVM, SSA-SVM, and DE-SVM, and the corresponding R values are 0.9555, 0.9539, 0.9413, and 0.9359, respectively. The research findings are beneficial to promote the application of cemented backfill coal mining technology.

Fiber content measurement of hybrid carbon and glass fiber reinforced thermoset composites

Hybrid carbon fiber and glass fiber reinforced thermoset composites are commonly used in structural applications throughout the energy, aerospace, automotive, and marine industries. The differing fiber types can be combined into a hybrid composite with the intent to efficiently utilize the beneficial properties of each type of reinforcement. The fiber fraction of each individual fiber type influences the mechanical properties of the overall composite. Measurement of the fiber fraction of each individual fiber type allows understanding and prediction of the mechanical properties as well as a method of quality control in manufacturing. A combination of a carbonization in nitrogen method for the measurement of fiber content in carbon fiber reinforced composites and an oxidation method to measure the glass fiber content are used for the first time. It has been demonstrated that the approach is effective at measuring the carbon fiber and glass fiber contents in hybrid glass and carbon fiber thermoset composites in both epoxy and vinyl ester resin systems.

Experimental Study on the Mechanical Properties, Water Absorption, and Fiber Degradation of Naturally Aged Glass Fiber and Polypropylene Fiber-Reinforced Concrete.

The main objective of this study is to better understand the performance changes of naturally aged glass fiber-reinforced concrete (GFRC) and polypropylene fiber-reinforced concrete (PPFRC), especially the degradation of fibers, which is of great significance for evaluating the durability of structures using these two types of composite materials. The mechanical properties, water absorption, and microstructures of GFRC and PPFRC at a curing age of three years, including their compressive strength, full curves of water absorption, fiber-matrix interaction, and fiber degradation, were systematically studied, and the related properties were compared with those at the curing age of 28 days. The degradation of fibers after freeze-thaw cycles was also studied. The results revealed the following. The water/binder ratio (w/b) affects the rate of increase of the long-term compressive strength of naturally aged concrete. In general, the water absorption of fiber-reinforced concrete (FRC) at the curing age of three years was found to be significantly reduced, but with the increases of w/b and the fiber content to the maximum values, the water absorption of the specimens cured for three years was higher than that of the specimens cured for 28 days. Moreover, with the increase of the curing age, the optimal glass fiber (GF) contents for reducing the water absorption decreased from 1.35% to 0.90% (w/b = 0.30), and from 0.90% to 0.45% (w/b = 0.35), respectively. The GF surface was degraded into continuous pits with diameters of about 200 to 600 nm, and the surface of the pits was attached with spherical granular C-S-H gel products with diameters of about 30 to 44 nm. The freeze-thaw cycles were found to have no significant effect on the pits on the GF surface and the granular C-S-H gel products attached to the pits, but caused a portion of the cement matrix covering the GF to fall off. The interfacial bonding between the polypropylene fiber (PPF) and the cement matrix exhibited almost no change in the PPFRC after three years of curing as compared with that after 28 days of curing. Furthermore, the cement hydration gel on the PPF surface was not significantly damaged by 150 freeze-thaw cycles.

Heat Analysis of Thermal Conductive Polymer Composites: Reference Temperature History in Pure Polymer Matrices.

This attempt aims at assessing heat generation in thermal conductive polymer (TCP) composites widely used in aerospace sectors. Temperature histories were investigated in both nonreinforced and glass-fiber-reinforced TCPs during abrasive milling. Glass/epoxy and glass/polyester composites with 30% unidirectional glass fiber content were prepared according to appropriate curing cycles. Type K thermocouples connected to a data acquisition system ensured the recording of temperature history along the trim plan during milling. Unexpectedly, when milling TCP composites parallel to fibers, peak temperature was found to be slightly lower than that recorded in nonreinforced polymers. The lateral surface of fibers acts to favor sliding friction, which limits heat generation at interfaces, while relatively low specific heat capacity and thermal conductivity of glass fiber disadvantage heat transfer. However, when milling perpendicular to fibers, the contact area between the tool and the transverse failure area of fibers increases drastically, hence involving severe friction at interfaces. This yields peak temperatures sensitively higher than those obtained in nonreinforced polymers. SEM inspections highlighted the failure modes dominating the material removal process in both nonreinforced and glass-fiber-reinforced polymers. The microcracks and debris observed at the trim plan explain, in part, the heat generation detected on temperature rate plots. Thus, heat conduction between phases governs sensitive surface finish integrity and tool lifetime and, hence, has great economic impact on the manufacturing steps.

Flexural Properties of Multi-Tow Structures Constructed from Glass/Polypropylene Tape under Various Manufacturing Conditions

In this study, a multi-tow structure that can provide load-bearing functionality was fabricated through a proposed consolidation process proposed using polypropylene-impregnated continuous-glass-fiber composite tape (glass/PP tape). The flexural properties of the multi-tow structure were analyzed to evaluate the influence of the processing temperature, processing speed, number of glass/PP tapes, and glass fiber content of the glass/PP tapes. The proposed process for constructing the multi-tow structure can generate straight, curved, and looped three-dimensional structures by using a multi-joint robot and instantaneous consolidation of glass/PP tapes. As the number of glass/PP tapes increased, the resin-rich area increased and the void volume fraction in the multi-tow structure increased from 2 to 5 vol%, while the flexural strength decreased. However, when the number of glass/PP tapes and processing temperature were adjusted appropriately, the flexural strength of the multi-tow structure that can be constructed at speeds 30 times faster than those of conventional pultrusion process was relatively superior. The results of a finite element analysis, confirmed that the inclusion of the proposed multi-tow structure in a bumper beam was effective in reducing deformation and absorbing the impact energy due to external loads.

Development and performance evaluation of wood-pulp/glass fibre hybrid composites as core materials for vacuum insulation panels

Thermal insulation is regarded as one of the key technologies to combat ever-increasing energy consumption. An efficient method to develop innovative and cost-effective core materials for vacuum insulation panels (VIPs) is proposed. The materials are natural and sustainable wood pulp fibre doped with various amounts of glass fibre as a reinforcing phase to create a hybrid multi-level network composite core material through the conventional wet papermaking process. The basic characteristics of both wood pulp fibre and glass fibre are studied, and the effect of glass fibre on the textural properties and thermal insulation performance of the composite core materials of the VIPs is investigated. The results showed that all core materials achieved an uniform dispersion of fibres, and the axes of the fibres were randomly in the three-dimensional (3D) network structure. Upon increasing the glass fibre content, the thermal conductivity of the VIPs gradually decreased due to structural changes in the core materials. Both the pore diameter and porosity increased with the glass fibre content. The thermal insulation of the developed VIP was comparable to those of most commercial VIP products. Thermal conductivities of 6.48 and 4.69 mW/(m∙K) were obtained for the VIP with 100% wood pulp fibre and wood-pulp/glass fibre composites (50% mass ratio), respectively. Furthermore, after 365 days of storage, the composite core material with 50% glass fibre maintained a thermal conductivity of 7.42 mW/(m·K) without a getter or desiccant. Even in the accelerated aging condition after 28 days, the increase in the thermal conductivity was less than 5.00 mW/(m·K).

Effect of Fibers on the Mechanical Properties and Mechanism of Cast-In-Situ Foamed Concrete

The cast-in-situ foamed concrete is inherently susceptible to cracks due to its brittleness under external loads. In order to improve its mechanical properties, this paper investigated the effect of fibers on the mechanical properties and mechanism of cast-in-situ foamed concrete with designed dry densities in the range of 300–800 kg/m3. First, the influence of density on the mechanical properties of foamed concrete was studied, and the applicability of the splitting test, bending test, and direct tensile test was analyzed. Secondly, alkali-resistant glass fiber (high elastic modulus) and polypropylene fiber (low elastic modulus) were selected to determine the optimal fiber length and content. Finally, failure mode analysis was carried out to explore the influence mechanism of fibers on the mechanical properties of foamed concrete. The results showed that the compression curve model of cast-in-situ foamed concrete was mainly divided into three stages: the elastic stage, the brittle stage, and the yield stage. There were still some problems in the application of direct tensile tests and splitting tests for foamed concrete materials, and only the bending test could be used to test the tensile strength of foamed concrete materials. For the foamed concrete with a designed dry density of 300–800 kg/m3, the compressive strength, elastic modulus, and tensile strength of foamed concrete increased upon increasing the casting density. The compressive strength, elastic modulus, and flexural strength of foamed concrete first increased and then decreased upon increasing the fiber content. The optimal fiber length was 6 mm, the optimal glass fiber content range was 0.2–0.6%, and the optimal polypropylene fiber content range was 0.4–0.8%. The fibers formed a bridge structure between the hardened products, which increased the adsorption force between the hardened products of foamed concrete, thus increasing its compressive strength and flexural strength.

Effects of basalt and glass fiber composites usage for strengthening on the cyclic behavior of brick infill walls

In the current study, the effects of 10 mm bilaterally applied basalt fiber reinforced concrete (BRC) and glass fiber reinforced concrete (GRC) plasters with different fiber content (1.0%, 2.0% and 3.0%) on the behavior of the brick infill walls were investigated. For this purpose, strengthened brick infill walls placed in a hinged steel frame on all four corners were examined comparatively with their non-plastered and ordinary cement plastered conditions under cyclic loading. The load carrying capacities, displacement ductility, stiffness degradation and energy dissipation capacities of infill walls were determined using obtained results. The test results showed that brick walls with 1.0% glass fiber and 2.0% basalt fiber content showed the best performance in terms of load carrying and energy dissipation capacity. Also brick wall with 1.0% glass fiber content has the lowest stiffness degradation decrease at the ultimate drift ratio. In addition to all these, it has been observed that the mechanical behavior of the walls strengthened with plasters containing different percentages of fiber has improved considerably compered to non-plastered and ordinary cement plastered brick walls. This situation reveals that basalt and glass fiber plasters can be used to strengthen the walls. It is recommended that this method can be used quickly and effectively in the reinforcement of masonry structures, which have a large amount in the existing building stock.

Expandable Graphite, Aluminum Diethylphospinate and Melamine Polyphosphate as Flame Retarding System in Glass Fiber-Reinforced PA6.

A flame retardant system based on expandable graphite (EG), aluminum diethylphosphinate (AlPI) and melamine polyphosphate (MPP) was investigated in glass fiber- (GF) reinforced polyamide 6 (PA6). Burning characteristics were evaluated via cone calorimeter, limiting oxygen index (LOI) and UL-94 tests. Thermogravimetric analysis (TGA) and coupled Fourier transform infrared spectroscopy (FTIR) was used to investigate the decomposition process as well as flame retardant modes of actions. Specifically, in the cone calorimeter tests, formulations containing EG showed excellent flame retardant properties for non-reinforced and reinforced PA6. The best performance was achieved for 25 wt.% glass fiber-reinforced PA6 containing solely 20 wt.% EG, corresponding to a measured pHRR of 134 kW/m2 and a total smoke production of 1.2 m2. Higher glass fiber contents of 45 wt.% (30 vol.%) revealed a lower char volume, which was attributed to both the limited space available for expansion and the sheer-induced reduction in particle size during processing. All of the reinforced PA6 formulations only achieved V2 classifications, but this was at low filling degrees (10 wt.%) for both net EG or EG/AlPi/MPP combinations. For GF-reinforced PA6 containing EG/AlPi/MPP mixtures, a synergistic effect was found to improve the oxygen index up to 30.6%.

Increase of the efficiency in hot gas welding by optimization of the gas flow

The standard hot gas welding process uses a nozzle system consisting of multiple round tubes. With the top nozzle system, the weld seam is encapsulated to minimize heat loss and allow better control of the hot gas flow. This significantly reduces the required heating time of the polymer. Temperature measurements and welding tests with plates of various thicknesses and burst pressure specimens are performed to verify the improvements of the top nozzle. For polyamides with different base polymers and different glass fiber contents, an average reduction in heating time of up to 50 % is possible on average. The achieved weld strengths or burst pressures for the tested materials are comparable or higher with the top nozzle system. The top nozzle makes the process more economical due to a short cycle time and lower gas consumption. It can be added to existing hot gas tools. In addition, a larger process window, shorter heating time and higher achievable temperatures with the top nozzle lead to a higher acceptance of hot gas welding in industries. New weld able materials in turn open up new application areas and markets.

ВЛИЯНИЕ ВИДА ПРИМЕНЯЕМЫХ ФИБРОВЫХ ВОЛОКОН НА ПРОЧНОСТЬ И ДЕФОРМАТИВНОСТЬ ДИСПЕРСНО-АРМИРОВАННЫХ ОБЛЕГЧЁННЫХ БЕТОНОВ

Fiber-reinforced concretes with improved strength and deformation characteristics are widely used in construction. The research is aimed to study the stress-strain condition of lightweight fiber-reinforced concrete, to plot stress-strain diagrams and analyze them. In total, four series of prism specimens are manufactured and tested. The first series is the control composition of lightweight concrete; the second series is lightweight concrete with a basalt fiber content of 3%; the third series is lightweight concrete with a glass fiber content of 3 %; the fourth series is lightweight concrete with a basalt fiber content of 1.5 % and 1.5 % glass fiber. The experimental studies demonstrate that lightweight concrete reinforced with basalt fiber has the highest deformability. In comparison with glass fiber, basalt fiber has a higher tensile strength and a higher elastic modulus. The fact that the concrete matrix and basalt fiber work together better is primarily due to the best mechanical characteristics of the basalt fiber. Further research prospects are determined in terms of determining the adhesion strength of various types of fibers with a matrix and studying the effect of this indicator on both the strength and deformation characteristics of lightweight concrete.

An Investigation of the Properties of Expanded Polystyrene Concrete with Fibers Based on an Orthogonal Experimental Design.

Expanded polystyrene (EPS) concrete is commonly used as the core material of commercial sandwich panels (CSPs). It is environmentally friendly and lightweight but has poor strength. Adding fibers can improve the microstructure of EPS concrete and reduce the weakening effect of EPS beads on the mechanical properties of concrete. An orthogonal experimental design (OED) was used in this paper to analyze the influence of length and content of polypropylene fiber (PF), glass fiber (GF), and carbon fiber (CF) on the physical and mechanical properties and micromorphology of EPS concrete. Among them, CFs have the most apparent impact on concrete and produce the most significant improvements in all properties. According to the requirements of the flexural performance of CSPs, the splitting tensile strength was taken as the optimization index, and the predicted optimal combination (OC) of EPS concrete with fibers was selected. The variations in the material properties, mechanical properties, and microstructure with age were analyzed. The results show that with increasing age, the dry density, compressive strength, and splitting tensile strength of concrete are markedly improved relative to those of the CSP core material and the control case (CC), and even the degree of hydration is improved.

Influence of alkali-resistant glass fiber on seismic performance of precast ceramsite concrete sandwich wall panels

Shear wall, which is a component commonly used in high-rise building to resist the side force, has been widely applied in earthquake-prone regions. In this paper, a new type of prefabricated alkali-resistant glass fiber ceramsite concrete sandwich composite shear wallboard is proposed, which is composed of the polystyrene insulation board set in the middle and the alkali-resistant glass fiber ceramsite concrete boards set at both sides. This type of sandwich composite shear wallboard solves multiple problems of ordinary wallboard insulation materials from the perspective of structural form, including hidden risks of fire and peeling-off. Research experience shows that alkali-resistant glass fiber has high tensile, bending, crack, impact and alkali resistance, so adding the alkali-resistant glass fiber into concrete can improve its strength, toughness, crack resistance and corrosion resistance. Due to the existence of fiber, the cracks of cracked wallboard will open and close repeatedly under low reversed cyclic loading, so it can effectively absorb more seismic energy. Besides, the ceramsite concrete is featured in comparatively small elastic modulus and light mass, which help to reduce the dead weight of the wallboard. In a word, this kind of wallboard can effectively weaken the impacts of earthquake force and improve the overall seismic performance of wallboard structure. Therefore, in this paper, three types of specimens are designed with different admixture volumes of alkali-resistant glass fiber, respectively: 0%, 0.3%, and 0.4%. Through the experimental study on the seismic performance of the specimens, the influence law of different alkali-resistant glass fiber content on the seismic performance of the specimens is obtained. The study results show: compared with ordinary wallboard, the cracking displacement of the specimens with 0.3% and 0.4% fiber admixtures are improved by 42.63% and 35.79% respectively. This indicates that the fiber can delay the cracking of the test piece and improve the functional coordination among various materials, thereby easing the deformation of the overall wallboard when bearing forces. When the admixture amount of fiber reaches 0.3%, the specimen shows excellent performance in various seismic indicators, such as hysteresis, ductility, and energy consumption, presenting good application prospects. However excessive fiber admixture in ceramsite concrete actually has no good effect on the overall performance improvement of the wallboard. Therefore, in practical construction, this type of fiber shall not be added randomly.

Experimental investigation on the mechanical behavior and damage of 3D printed composites under three-point bending

Three-dimensional (3D) printing has been triumphantly applied for the manufacture of various composite components. In this work, acoustic emission (AE), X-ray micro-computed tomography (Micro-CT) are used in conjunction with digital image correlation (DIC) measurement to investigate the mechanical behaviors of 3D printed continuous fiber reinforced composites under three-point bending test. Meanwhile, several mechanical experiments are carried out to study the flexural properties of three kinds of composite specimens, among which the specimens with larger glass fiber content exhibit more superior mechanical properties. Furthermore, AE response characterizations and microscopic damage morphology are also examined. In consequence, the complementary nondestructive testing (NDT) technology combining AE, DIC, and Micro CT is successfully applied to evaluate the mechanical behaviors of 3D printed composites, and the flexural deformation and damage are comparatively investigated for different composite specimens. The cross-validation results of cluster analysis (k-means), K-Nearest Neighbor (KNN) and principal component analysis (PCA) show that AE parameters including frequency, amplitude, and RA value (rise time divided by peak amplitude) are closely associated with the damage process of different specimens. The results show that the PCA can confirm the selected K-means cluster analysis parameters (peak frequency and peak amplitude) and the dimensionality reduction effects of 20% glass fiber specimens have the best results, indicating that the proportion of the principal components extracted can represent the original parameters is 81%. It was also confirmed that the supervised learning KNN algorithm corresponding to different damage patterns can verify the unsupervised learning k-means cluster. Correspondingly, the strain fields characterized by DIC are reasonably matched with the AE signal responses. In addition, the critical damage and delamination mechanisms of the 3D printed continuous fiber reinforced composites are clearly revealed by Micro-CT characterization.