Material Test Results Research Articles

Effects of Anisotropic Mechanical Behavior on Nominal Moment Capability of 3D Printed Concrete Beam with Reinforcement

In this study, 3D-printed reinforced concrete beams were tested for flexural performance and compared with the analytical model based on the material test results. Two cementitious mixes (PSU and GCT) were designed for concrete printing and were mechanically tested and compared. Anisotropies in the compressive strength and modulus of elasticity of printed concrete were observed, applied to the analytical prediction of flexural bending behavior, and validated by actual test results. Significant differences between analytical predictions and experimental tests of the bending behaviors of the printed concrete beams were observed. Furthermore, higher compressive strengths and moduli of elasticity were observed when the loading direction was perpendicular to the printed layers or with the PSU mix. The effect of anisotropic mechanical properties on a reinforced beam was compared to the flexural bending tests for both mixes. The analytical model based on the material test results was compared to the flexural bending test results. The significant errors in the prediction of printed concrete’s structural performance, from 10% to 50%, suggest that factors other than reduced compressive strengths may influence the structural behaviors of printed concrete beams.

Applicability analysis of induction bending process to P91 piping of PGSFR by high-temperature fatigue test

The application of the induction bending process in pipe fabrication is expanding across industries, significantly reducing leakage by minimizing welded sections in curved pipes. In this study, the applicability of the induction bending process to P91 bent pipes of PGSFR was analyzed, focusing on both material fatigue tests and structural fatigue tests for induction bent pipe at high temperatures. First, both high-cycle and low-cycle fatigue tests on specimens from the bent pipe were carried out at 550 °C to confirm that the fatigue properties meet the ASME Code's fatigue requirements. Second, material constants for a Chaboche combined hardening model were identified by using the material test results and an inelastic finite element analysis of the P91 bent pipe were performed to determine the fatigue test load for structural test effectively. Lastly, a high-temperature fatigue test on the bent pipe structure was performed to assess its structural integrity and post-test non-destructive examination confirmed that no fatigue cracks developed, and thereby affirming the applicability of the P91 bent pipe.

PENGARUH PENAMBAHAN SERAT BAMBU PADA PEMBUATAN PAVING BLOCK TERHADAP KUAT TEKAN

Bamboo is widely used for various forms of building construction, such as houses, as roofs, columns and foundations. Apart from that, the remainder of its use will become waste. One of the building materials that is often used is paving blocks as an alternative ground surface cover that can be used for road pavement, parking lots, pedestrians, parks, etc. The aim of this research was to determine the effect of adding bamboo fiber with variation of 1%, 3%, and 5% on the compressive strength of paving blocks. The method used in this research is the experimental method. Primary data consists of material testing results and paving block compressive strength. Research was conducted at the Structures and Materials Laboratory, Departement of Civil and Mining Engineering, Ketapang State Polytechnic. From the results of the compressive strength testing of paving blocks that have been carried out, the highest average value of compressive strength of paving blocks with a variation of 1% is 320.01 kg/cm2 which corresponds to the quality concrete C used for home garage pavement, pedestrian circulation, and parking lot.

Determination of the combustion heat of several new energetic materials based on a small-mass combustion heat measurement device

ABSTRACT A device for determining the combustion heat of small mass for energetic materials (EMs) on the basis of 3D thermoelectric sensing technology was established. The combustion heat test results of dense ring energetic materials (TPNA, MNTIP, NTPA, OPTO, TTPA, and NTPNA) were - (2079.00 ± 2.6), - (3042.06 ± 6.2), - (2498.86 ± 8.2), - (1962.07 ± 8.3), - (2546.29 ± 3.5), and - (2792.87 ± 2.7) kJ • mol−1, respectively. The combustion heat test results of multi ring energetic materials (NPTTA, DNPOF, BNPBT, DNTI, BDNPBT, BDNPT, BTNBHT, AFAOT, and ATDAT) were - (3656.45 ± 3.5), - (3551.13 ± 4.6), - (4692.58 ± 25), - (3200.62 ± 8.3), - (5145.31 ± 33), - (3714.15 ± 11), - (7930.23 ± 6.5), - (2845.06 ± 2.5), and - (2000.18 ± 4.5) kJ • mol−1, respectively. The standard uncertainty of the test results ranges from 0.13% to 0.43%, indicating that the new combustion heat measurement device can be widely used to determine the combustion heats of small amounts of EMs.

Consistent memory surface model for plateau and hardening regions

Mild steels are frequently used in building structures because of their high strength, productivity, processability, and weldability. One key feature of mild steels is their yield plateau, which is followed by a hardening region in the stress–strain relationship. During large earthquakes, building members can experience a large plastic strain whose amplitude is difficult to predict beforehand. Constitutive equations applicable to the full-range strain field are necessary for accurate structural safety evaluation. This study provides novel constitutive equations for the plateau region, capable of reproducing a yield plateau. A set of hardening constants was proposed to satisfy the consistency condition of the plastic multiplier under any loading pattern. The closed form of the stress–strain relationship was derived to calibrate the material constants. The material constants were calibrated using two types of material test results. The results of the proposed model were consistent with the material test results under cyclic loading at various strain amplitudes. This was validated by comparing the shear buckling and lateral torsional buckling test results of an H-shaped beam with the finite element analysis (FEA) results. The numerical demonstration also highlighted the significance of not only material constitutive laws but also the introduction of residual stress and initial imperfections in reproducing the pre- and post-buckling behaviors. The convergence of the residual force for the proposed model was equivalent to those of the authors’ previous model and the Chaboche model. These results indicate that the proposed model can predict hardening phenomena at the material and structural levels in the plateau and hardening regions.

Pengembangan E-Modul Berbasis Ethno-STEM pada Materi Geometri

This research is motivated by problems in the learning process. In this problem, it has an impact on the problem-solving ability of mathematics students at UIN K.H. Abdurrahman Wahid Pekalongan, therefore the development of e-module-based learning was made. This study aims to find out how to reconstruct the concept, validity and effectiveness of mathematics e-modules in local Javanese culture in ethno-STEM-based geometry learning. This research is R&D type with ADDIE development model. Which is proven to be valid and effective, the results of material and media validation tests reach 68% and 78% with valid cateogries.

Experimental and numerical investigation of austenitic stainless steel (304 type) slit damper structural behavior

Carbon steel dampers have been applied for the seismic retrofitting of new and existing building structures. Experimental and numerical studies on the seismic response characteristics and reinforcement effects of applying stainless steel for the seismic retrofitting of building structures were recently conducted in the United States and Europe. Owing to its superior corrosion resistance, durability, sustainability, and fire resistance compared to carbon steel, austenitic steel is widely used as a structural material. In this study, experiments and numerical analyzes were performed to investigate the structural behavior and energy dissipation capacity of austenitic stainless steel slit dampers. The material test results show that austenitic stainless steel (STS304) underwent noticeable strength enhancement after yielding under cyclic loading compared to steel under monotonic tensile loading. The ultimate strength of the specimens also tended to increase in each cycle due to the cyclic hardening effect. A finite element (FE) analysis model was developed to predict the hysteretic behaviors of stainless steel dampers based on the cyclic material test results. The validity of the FE analysis model was verified through comparison with the test results and stress and strain distribution on critical section were discussed. In addition, the hysteretic behavior of the single story frame with chevron brace and stainless steel slit damper was investigated and compared with that of carbon steel damper.

Topological structure of Au nanoparticles@salix leaf-like metal–organic framework-MXene for highly sensitive determination of carbendazim

Herein, a novel ternary composite material has been proposed for the electrochemical detection of carbendazim (CBZ) pesticide. Such Au nanoparticles@zeolitic imidazole framework-L-Ti3C2Tx (AuNPs@ZIF-L-Ti3C2Tx) can be obtained by using few-layer Ti3C2Tx and AuNPs@ZnO as the precursors. The original synthetic route leads to the distinguished morphology of AuNPs@ZIF-L-Ti3C2Tx, which exhibits the salix leaf-like morphology that is accompanied by two kinds of topological structures including the dart-like and carambola-like shapes. More importantly, the unique structure of AuNPs@ZIF-L-Ti3C2Tx contributes to high-performance sensing for the determination of CBZ. A series of control experiments has been performed in order to investigate the structure-activity relationship and sensing mechanism of AuNPs@ZIF-L-Ti3C2Tx. According to the material characterization results and performance testing results, the synergistic effect of AuNPs, ZIF-L and Ti3C2Tx is considered as the key of high-efficiency reaction interface that leads to the electrocatalytic oxidation of CBZ. The established electrochemical sensor based on the non-enzymatic AuNPs@ZIF-L-Ti3C2Tx shows a low limit of detection is 1.2 nM. Notably, the highly sensitive determination of CBZ can be realized by AuNPs@ZIF-L-Ti3C2Tx, owing to 66,684 μA mM−1 cm−2 of sensitivity. The two-stage linear detection ranges are 0.01–0.20 μM and 0.20–20.00 μM. The potential application of AuNPs@ZIF-L-Ti3C2Tx has been displayed to develop high-performance sensor.

Charpy and Izod Method Impak Strength Analysis on ST 37 Steel with Temperature Variations

This research is impact testing using the Charpy and Izod methods, temperature variations of 1500 C, 2500 C and raw material as the research variable. The results of the Charpy test with a variation of 150 0C obtained a maximum absorbed energy of 97.65 J, with an impact value of 0.222 J/mm2. Then the maximum energy absorbed through testing at a temperature of 2500C is 78.28 Joules and the impact value is 0.177 J/mm2. Furthermore, the raw material test results showed that the maximum energy absorbed was 145.96 J with an impact value of 0.330 J/mm2. Izod testing with a temperature of 1500C obtained a maximum absorbed energy of 60.94 J with an impact value of 0.101 J/mm2. Furthermore, the maximum energy absorbed at a temperature of 2500C is 36.83 Joules and the impact value is 0.061 J/mm2. The raw material test results show that the maximum energy that can be absorbed is 80.53 J with an impact price of 0.133 J/mm2

Sustainable Utilization of Marble Dust and Rice Husk Ash as a Partial Substitute for Fine Aggregate in Concrete

A sustainable method for partially substituting fine aggregate in concrete with marble dust and rice husk ash is described. This approach focuses on the utilization of these materials to minimize environmental impact while maintaining the integrity of the concrete structure. In this study, the fine aggregate was partially substituted with marble dust and rice husk ash. Additionally, sisal fiber was incorporated as secondary reinforcement for concrete at percentages of cement by weight. Concrete has good compressive strength but is weak in tension and bending. Thus, sisal fibers were added to enhance the mechanical properties. Sisal fibers were included at 0.1% and 0.2% of cement weight for varying percentages of mineral admixture substitution. 30% of cement was replaced with mineral admixtures, with replacement levels of 0%, 10%, 15%, 20%, and 30% of marble dust and rice husk ash. The slump cone and compaction factor tests were performed on fresh concrete mixes to determine workability. Standard cubes, cylinders, and prisms were cast to evaluate the compressive, split tensile, and flexural strengths of the hardened concrete. The results show that the replacement of cement with marble dust and rice husk ash with sisal fiber as an additional reinforcing material shows considerable improvement in tensile and flexural strength. The material properties and test results are presented graphically.

Coupling multi-physics models to corrosion fatigue prognosis of high-strength bolts in floating offshore wind turbine towers

Floating wind offshore turbines (FOWTs) tap into the immense Aeolian resource in deep-water oceans. The turbine structure, especially in ring-flange (RF) connections, are highly prone to corrosion fatigue (C-F) deterioration due to the combination of strong wind-wave loads, structural flexibility, and high corrosivity. This study provides innovative insights into the C-F deterioration of FOWT towers by integrating site-specific data, material test results, multi-physics simulations, and deterioration models. A probabilistic C-F (PCF) evolution model is tailored for bolts in RF connections, accounting for multiple failure modes. Concurrently, the corrosion test data are adopted to estimate the corrosion rate from the site-specific ambient conditions, including the temperature, humidity and airborne salinity. The result indicates a strong correlation between wind-wave spatial distribution and C-F damage, for which the critical bolt aligns with high-velocity winds. Meanwhile, the bolt deterioration is accelerated under high corrosivity, risking premature failures. Moreover, compared with the traditional fixed-bottom foundation, the floating platform amplifies the tower dynamics in both mean value and variation, which in turns escalate stress ranges in bolts. The findings underscore the importance of monitoring C-F deterioration in FOWT structures and highlight the potential of condition-based maintenance.

Performance of steel tube reinforced concrete-filled weathering steel tubular members under lateral impact loading

Weathering steel tube is superior to mild steel tube in corrosion resistance, but it is less used in engineering projects due to its high price. To balance the performance and cost, mild inner steel tube reinforced concrete-filled weathering steel tube (STRCFWST) members are proposed in this study, and the lateral impact loading test is carried out. The impact responses of concrete-filled weathering steel tube (CFWST) members and STRCFWST members are studied and compared experimentally. It is indicated that the presence of the inner steel tube can remarkably enhance the impact resistance of STRCFWST members. The outer steel tube has a stronger influence over the impact resistance as compared to the inner steel tube. A constitutive model for the weathering steel is developed based on the material test results. The impact performances of STRCFWST, CFWST and conventional CFST members are compared and discussed using numerical simulation. Finally, parameter analysis of the impact performance of STRCFWST members is carried out by taking into account the actual stress state of bridge bents. The results show the proposed model can predict the mechanical behaviors of weathering steel, making it suitable for numerical modeling. The CFWST member suffers fracture failure a little earlier than the CFST member. A large diameter-thickness ratio is recommended for inner steel tubes on the premise of guaranteeing construction conditions. The optical area ratio of internal and external steel depends on the prices of weathering steel and mild steel, and the diameter ratio of inner and outer steel tube.

Thermoforming of partially biodegradable hybrid thermoplastic composites for bone plate applications

This study introduces a partially biodegradable composite of carbon fibre/Nylon and Magnesium alloy (Mg) wire/polylactic acid (PLA) for bone fracture healing, focusing on its mechanical properties, with Young's modulus, flexural strength, and interlaminar shear strength investigated under different forming conditions. The Mg wires were subjected to mechanical and chemical treatments (with 80 and 220 grit sandpapers and phytic acid) to improve mechanical performance. Optimal treatment conditions were determined, and material test results were compared with microscopic observations. Using the recommended forming conditions, a hybrid composite bone plate was thermoformed for potential medical use.

Performance of additively manufactured Ti6Al4V ELI finger joints: biomechanical testing and evaluation for arthritis management

Abstract Approximately 24 out of every 100 adults in the United States, or 58.5 million people, have arthritis, which refers to a condition that causes pain and inflammation in a joint according to US National Center for Chronic Disease Prevention and Health Promotion. Osteoarthritis is the most common type of arthritis, and it may damage almost any joint but mainly occur in hands, hips and knees. While there are several joint replacement options for hips and knees, there are only limited options for finger joints. In this paper, we report on several aspects of testing of novel finger joints: testing apparatus design, cadaveric performance test and material testing results of titanium joints using 3D-printed Ti6Al4V extra low interstitial (ELI). Soft cadaveric hands with finger joints were surgically replaced by additively manufactured titanium joints following the exact same anatomy of the cadavers. These small joints were engineered to mimic the biological and natural movements of fingers. The apparatus, methodology and results of biomechanical tests were deployed to evaluate and validate the joints particularly those of titanium joints manufactured via laser powder bed fusion methods (PBF-L/M).

The Development Of Science Literacy Based Digital Teaching Materials To Improve Students Critical Thinking On The Sub Matter Of Energy Flow And Biogeochemical Cycles

This study aims to develop science literacy-based digital teaching materials that are feasible, practical, and effective for improving students' critical thinking on the sub-materials of energy flow and biogeochemical cycles. This type of research is research and development (RnD). The method used in research and development refers to the ADDIE development model. The population in this study were students in grades XI Mipa and X SMA Negeri 15 Semarang in the 2022/2023 academic year. MIPA 7 for small-scale trials and 60 students from each of 30 students X-1 and X-2. The data collection techniques used were interviews, questionnaires and tests. Based on data analysis, the feasibility test results of science literacy-based digital teaching materials by material experts amounted to 85% and media experts amounted to 82%. The results of the practicality test analysis by teachers in both scale trials were 90% and the results of the practicality test analysis by students in both scale trials were 84%. From all the results of the analysis, it is included in the category of very feasible and practical. To determine the effectiveness of science literacy-based digital teaching materials, pretests and posttests in classes X-1 and X-2 were conducted and then calculated using the N-Gain test based on aspects. The results of the N-Gain test for the science literacy aspect in both classes were 0.64% and the N-Gain test for the critical thinking ability aspect in both classes was 0.62%. This shows that classes X-1 and X-2 on improving science literacy and critical thinking skills are at moderate criteria. It can be concluded that the use of science literacy-based digital teaching materials is effective for improving students critical thinking skills in the sub-materials of energy flow and biogeochemical cycles.

Comparison Of The Pull Strength Of Sisal Lamina Matrix Polymer Fiber Composite Materials (Agave Sisalana)

Composites are one of the material engineering technologies developed today because composites can combine several material properties that differ in characteristics into new properties by the planned design. The purpose of this study was to determine the mechanical properties of the influence of the combined arrangement of lamina angle variations and the composition of fiber and matrix mixtures. This study uses polyester resin, catalyst, and sisal fiber as materials in the manufacture of composite materials. In specimen manufacturing refers to ASTM D 638-02 type 3 test standard for tensile tests. The tensile test results of sisal fiber lamina composite materials assuming a composition ratio of 5% fiber and 95% resin produce maximum tensile stress of m = 16.9854 N/mm2 and a maximum strain of É› = 4.5232% while assuming a composition ratio of 15% fiber 85% resin produces maximum tensile stress of sm = 40.1422 N/mm2 and maximum strain of É› = 8.9744 %, Based on the test results, the addition of fiber mixture composition increases the tensile strength and toughness of the material. The composition of 5% fiber 95% and 15% fiber 85% resin (15S-85R)produces a maximum tensile stress of sm = Â 45.1823 N/mm2 and a maximum strain of É› = 9.6849 % with a maximum load Fm = 10902.4996 N. The more fiber contained in the sisal fiber lamina composite material, the higher the tensile stress produced, this shows the tension is directly proportional to the number of fibers contained in the composite.

Quality Characteristics, Cold Chain System, Yield and Productivity of Frozen Tuna (Thunnus albacares) Steak Processing

One of the prospective products that can be developed from tuna is frozen tuna. One processing technique to preserve tuna fish is generally through freezing. F frozen tuna steak is one of the many processed tuna products produced through freezing. The aim of the research is to analyze quality characteristics, application of the cold chain system, calculation of yield and productivity in the processing of frozen tuna steaks at PT. Wahyu Pradana Binamulia. The research method uses a qualitative descriptive method with research stages including process flow observation, organoleptic quality measurements, microbiology (ALT, E. coli, Salmonella), chemistry (histamine), yield calculations, productivity calculations. The data collection method was by directly following processing activities and interviews for the frozen tuna steak processing process, while other data was carried out by testing. The results of the research obtained the processing flow of frozen tuna steak at PT. Wahyu Pradana Binamulia has 23 stages. The organoleptic test results for raw materials have a value of 8 and the final product has a value of 9. The raw material test results for ALT are 6.2 x 103 col/g, Coliform <3 MPN/g, E. coli <3 MPN/g and Salmonella with negative results. The final product test results were ALT 5.5 x 103 col/g, Coliform <3 MPN/g, E. coli <3 MPN/g, and Salmonella with negative results. The histamine test results obtained were 6.9 ppm in the raw material and 7.4 ppm in the final product. Observation results of raw material and product temperatures ≤4.4°C, room temperature ≤20°C and air temperature ≤4.4°C. The yield at the weeding stage was 78.37%, loin formation was 69.40%, dark meat separation and skin removal was 60.77%, trimming was 45.11%, steak formation was 40.48%, retauching was 39. 02%. Employee productivity results at the weeding stage had an average value of 1,214.23 kg/hour/org, for the trimming stage 530.12 kg/hour/org, for the steak formation stage 599.66 kg/hour/org. It can be concluded. The research conclusions show that the quality of raw materials and frozen tuna steak products has met the established SNI standards.

Application of the Markov chain Monte Carlo analysis through a lumped model in ablation test results of ablative and reradiative materials

High heat fluxes generated by aerodynamic heating or rocket propellant burning create a high demand for the use Thermal Protection Systems (TPS) to prevent damage or malfunctioning in payloads and rocket parts. Thermophysical and ablative properties of TPS materials are needed for their design, but are commonly unavailable or difficult to access experimentally. Besides, materials present different responses to high heat fluxes according to their composition and manufacturing process. Inverse heat transfer problems were initially studied to determine not known variables in thermal behavior of space vehicles and have proven to reach reliable properties values of ablative materials. This work applies an already validated methodology, using the Markov chain Monte Carlo (MCMC) method applied to a lumped physical model of ablation, to determine thermophysical and ablation properties of different composite materials starting from arc-jet ablation results. The direct problem with a more refined mesh and the obtained values of these properties was used and the numerical results were compared to the experiments, presenting good agreement and resulting in lower rms values, when compared to original values extracted from literature.

Do chewing simulators influence the test results of dental materials? Systematic review

Investigate whether different results about the physical properties of the same biomaterial frequently found in the literature are due to chewing simulator deficiency. A literature review was performed by searching for data on indicators of test accuracy, reproducibility, maintenance of test parameters during all experiments, and standards in the articles or in the sites of manufacturers. The database searched was CAPES PORTAL, and the keywords used were “bite force” AND “simulator”, “chewing simulator” and “mastication simulator”. Including criteria for the papers are publication filter date of “January 1, 2016”, articles in English, Spanish and Portuguese language were accepted. The first 100 papers that seemed suitable when considering the title and abstract were recovered. Only one simulator used for food property studies had the parameters searched. In the customized simulators for biomaterial properties, only one showed standards, and 8 showed all other parameters searched. All manufactured simulators showed all parameters searched, and only two manufactures did not show standards. Based on the data obtained, the disparate results of experiments with dental materials appeared to be more related to the test conditions than to the testing machines. Knowledge Transfer Statement The findings of the current review suggest that the chewing simulators used in preclinical research are reliable, bringing safety to restorative processes regarding the material. Any difference in preclinical investigations about dental material physical properties is due to test conditions other than chewing simulators.

Effect of nanomaterials (carbon nanotubes, nano-silica, graphene oxide) on bond behavior between concrete and reinforcing bars

The purposes of this study are (i) to evaluate the mechanical properties of triple hybrid-reinforced concrete mixed with carbon nanotubes, nano-silica, and graphene oxide and (ii) to determine the effect of these properties on the bond strength. First of all, compressive strength and splitting tensile strength tests were performed to evaluate the mechanical properties of triple hybrid-reinforced concrete. It has been observed that the flexural strength of concrete increases and the Poisson's ratio and volumetric strain decrease with the incorporation of nano-materials, and the effect is most pronounced when graphene oxide is added. Next, pull-out tests were conducted using a total of 21 specimens of triple hybrid-reinforced concrete. Similarly to the material test results, the bond performance of triple hybrid-reinforced concrete was found to be the highest, which can be attributed to the minimal volumetric deformation of the concrete. By this, the bond strength of Triple hybrid-reinforced concrete was evaluated, taking into account the mechanical properties. When considering Poisson's ratio and flexural strength, it was possible to predict them relatively accurately. In future research, it will be necessary to analyze additional mechanical properties such as friction coefficient and shrinkage strain of nano concrete to incorporate them into the bond strength model.