Italian Group Fracture (IGF): E-Journals / Gruppo Italiano Frattura
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Experimental and numerical inspection of cracks in ferrule cracking of BK1 cement crusher
Get PDFThis article defines the main actions planned in the procedure of non-destructive testing and analysis of defects in the BK1 industrial mill of the cement plant of the GICA group. One of the subjects attracting the attention of researchers and engineers was the propagation of cracks in the shell of the BK1 mill, which behaves like perforated plates. This inspection technique makes it possible to position and size defects (cracks) in the plates. The objective of this work is the detection of cracks in the shell of the BK1 cement mill. In order to avoid bursting of the crusher, the preventive technique of ultrasonic inspection using a multi-element translator is used, while minimizing downtime and increasing production. Found Results allow us to determine and analyze the different types of defects, which will be repaired. It was concluded that the stress concentration at the assembly holes, the vibration effects and gradient of the temperature due to the effect of welding were the causes great residual stresses at the level of the weld. We note the addition of a mass of weld during the repair of the cracks is one causes of the stress concentration
Investigation on Microstructure, Hardness, Wear behavior and Fracture Surface Analysis of Strontium (Sr) and Calcium (Ca) Content A357 Modified Alloy by Statistical Technique
Get PDFThe aluminum alloy are extensively used in several industrial applications. Stir casting is one of the most frequently accepted methods. In the present investigation, how the microstructure, mechanical and wear mechanics of A357 alloy were impacted by the presence of Sr/Ca was investigated. The outcomes revealed that addition of elements (Sr/Ca) enhance the microstructural features. Uniform dispersal of particulates (Sr/ Ca) in Al357 alloy and also the modified structure of silicon (Si) were observed. Hardness of modified alloy was evaluated by using hardness tester. A result reveals that hardness of modified alloy was improved by increasing in the Sr/Ca content. The wear rate of modified alloy was evaluated by using Pin and Disc wear test rig. Test trials were conducted according to Taguchi technique. L27 array was implemented for evaluation of data. The effect of varying parameters (factors) on wear loss and COF were analyzed using ANOVA (Analysis of Variance) method. ANOVA outcomes shown that, the Sr/Ca content has a better significant impact on wear behavior and COF of the modified alloy. A wear fractography result shows the internal fracture structure of a wornout surface which was studied by SEM analysis
Modelling of fresh properties and strength activity index with microstructure characterisation of ternary cement incorporating waste glass and granulated blast furnace slag
Get PDFResearch in innovative construction materials has focused on utilising supplementary materials in cementitious composites to promote sustainable development and reduce CO2 emissions. Within this context, this study aims to investigate the fresh properties and assess the pozzolanic activity of ternary blended cement by incorporating two industrial waste materials, namely waste glass (WG) and granulated blast furnace slag (GBS), as cement replacements up to 30%. A mixture design approach was employed for composition optimisation, and mathematical models were implemented to achieve this. XRD and SEM/EDS analyses were conducted to examine the structure and composition of the cementitious matrix.The results indicate that the setting time was prolonged compared to the reference mixture. Furthermore, based on the results of the SAI (Strength Activity Index) test, an acceptable level of strength development was demonstrated, confirming that WG and GBS possess the potential to replace cement while meeting the minimum strength requirements outlined in the specifications. Microstructure analyses revealed good adhesion between WGP, GGBS, and the cementitious binder. This research contributes to the development of eco-efficient binders that exhibit increased cement replacement ratios and qualities comparable to, or even superior to, traditional cement systems
The behavior of reinforced lightweight concrete beams with initial cracks
Get PDFThis research examines the performance of reinforced lightweight concrete beams subjected to several degrees of damage (50%, 60%, 70%, and 100%). It can use a sheet made of Carbon Fiber Reinforced Polymer (CFRP) to reinforce. The Full U-wrapping rehabilitation method was tested in the presented experimental program. In this method, CFRP sheets are attached to the bottom only and the side and bottom of the beam section. Experiments proved that the service load (Ps) increases by 7.06 % from a damage level of 50 % to 70 %, rises by 1.21 % from a damage level of 60 % to 70 %, and falls by 3.07 % from a damage level of 100 %. The result also rose for the fortified sample by 11.99%. Increases of 42.67 %, 33.07 %, and 23.73 % in the stiffness ratio (k) were observed at damage intensities of 50, 60, and 70 %, respectively. Damage at lower severity levels is increasing at a faster rate. The ductility of the restored LWC beams is more excellent than the control, as with the stiffness. Damage levels of 50%, 60%, and 70% saw increased ductility of 35.60, 34.92, and 34.69 %, respectively
Mechanical and Fractured surface characterization of epoxy/red mud/fly ash/ aluminium powder filled hybrid composites for automotive applications
Get PDFIn recent decades, one can observe a great increase in the replacement of traditional materials with polymer composites in high-strength and lightweight applications. High fuel consumption by automobile and aerospace vehicles built from legacy alloys has been a great challenge to material engineers. This has called for researches into lighter material development of the same or even superior mechanical properties to the existing materials in this area of applications. In the present study, epoxy based simple and hybrid composites were prepared with the incorporation of industrial waste as fillers at different weight percentages. Effect of filler type, combination and its concentration on mechanical properties such as tensile, impact and flexural strength were investigated. SEM analysis was carried out for fractured surfaces of composites, wherein minor voids, crack initiations and filler pullouts were seen indicating the necessity of coupling agent addition for still better performance. Among hybrid composites, epoxy/fly ash/red mud/aluminium powder (91/6/1.5/1.5 wt%) has showed the highest ultimate tensile modulus, flexural strength and hardness value compared to other composites under study
Fracture analysis of defect Chlorinated Poly Vinyl Chloride pipes based on burst pressure and prediction their fraction of life
Get PDFMost Chlorinated Poly Vinyl Chloride (CPVC) resins contain 63-69 % chlorine, in particular those used for the extrusion of plumbing tubes, due to this chlorination of basic PVC, CPVC offers a mixture of corrosion resistance and low installation costs for its main applications requiring service in non-ambient conditions. CPVC replaces copper owing to its economic gain and by virtue of its pressure resistance characteristics. In this article, we have been interested in fracture analysis and damage modeling of CPVC tubes by subject CPVC samples to burst pressure tests. We performed a set of burst tests on virgin and artificially damaged CPVC pipe at different notch lengths, then submitted the specimens to burst pressure tests, in addition to recording the pressure and time during these tests for use in conducting the study. The results of the burst tests were exploited to estimate the damage and reliability of the material, these two parameters allow us to follow the degradation of the pipes used; subsequently, we determined a new relationship between these two parameters through the fraction life. This makes it possible to predict the moment of damage acceleration and to intervene at the right time for engaging predictive maintenance
An assessment of HDPE fillers and Fiber Wrapping on the strength of Reinforced Concrete
Get PDFFiber-reinforced polymer (FRP) is the most promising technique in the present era to bring sustainability, reliability, and pseudo ductility to concrete structures due to its superior properties. Thermoplastic and thermoset polymers are the most thrown-out synthetic waste that contributes to environmental pollution for a long time. Knowing this issue an attempt was made to use High-Density Polyethylene Fiber (HDPE) fillers of size 40x2 mm has been used in concrete. This investigation aims to estimate the integrity effect of HDPE fillers incorporation and wrapping of concrete with Basalt fiber mats (BFM) and Geo-textile fiber mats (GFM) on split tensile strength, shear strength, and impact resistance as per standards. Results indicate that the addition of an optimum quantity of HDPE has a significant effect on improving the tensile, shear, and impact strengths. Adding HDPE fillers in the range of 0.5 - 1.5% in concrete samples wrapped with Basalt and Geo-textile fiber mats showed an increased tensile strength of up to 14.06% and 7.40% respectively with that conventional concrete. Further, wrapping of concrete using Basalt fiber and geotextile fiber mats showed a 4.16% and 20% increase in shear strength for 0.5% HDPE-incorporated concrete samples. Higher impact resistance was also observed for HDPE-added and fiber-wrapped concrete samples
Free vibration analysis of the structural integrity on the porous functionally graded plates using a novel Quasi-3D hyperbolic high order shear deformation theory
No full textIn this study, a novel quasi-three dimensional hyperbolic high-order shear deformation theory (quasi-3D HHSDT) is developed for free vibration analysis of porous functionally graded plates (FGPs). There are six unknowns in the current displacement field, and no shear correction factor is required. The mechanical properties are varied continuously through the thickness of porous FG plates using a modified power law function while considering the effect of porosities on the plate’s structural integrity. Two distinct porosity distribution models are considered, including even and uneven porosity distributions. The Navier technique is employed to obtain the closed-form solutions of motion's equations. An exhaustive parametric study is presented to show the influence of the different parameters on the fundamental frequencies
Study of defects influence on chlorinated polyvinyl chloride pipes damage and analysis of their fracture
Get PDFIn several industrial applications, plastic, composites and ceramics replace a number of metallic structures such as copper, aluminum and steel. Most recently installed piping water and gas systems in the world are made of thermoplastic due to its advantages, for example, low cost, ease of fabrication and corrosion resistance. In this work, the chosen material is chlorinated polyvinyl chloride (CPVC); the best one used to transport cold and hot water beside simplicity of installation. Notwithstanding, the pipes in service are submitted to different loads, related to environmental, thermal and mechanical effects which procure to mechanisms of degradation. The aim of this article is to assess the effect of the defect on CPVC pipes, through a study of the defect criticality in the form of semi-elliptical, then the ability to predict defected pipes residual life. Therefore unexpected and sudden failure caused by pipes accelerated damage. Therefore, we performed burst tests on both pre-damaged CPVC pipes and virgin ones. To lead our work in this paper, interested in the damage modeling and the failure analysis of CPVC pipes, we adapted the model of unified theory static damage, originally developed in fatigue. We used burst pressure tests to identify the limits of three damage progression phases and, in turn, to calculate the critical life fraction at which these flaws become harmful. Furthermore, we identify the critical depth for the studied defect. These results and techniques enable industrialist s to anticipate this structures service life under these conditions after that set up a robust system of maintenance to ensure a reliable and safe functioning of the structure
Retrofitting of Box Section Concrete Beams to Resist Shear and Torsion Using Near-Surface-Mount (NSM) GFRP Stirrups
Get PDFThere are a few kinds of research about box section Reinforced Concrete (RC) beams under the effect of combined shear and torsional stresses. In the present research, the concept of adding external strengthening, in the transverse direction, is adopted. The paper focuses on using Glass Fiber Reinforced Polymer GFRP ropes as near-surface mount stirrups. Nine box-section concrete specimens were decanted and tested. Three variables are adopted, (1) GFRP stirrups diameter, (2) GFRP stirrups inclination, and (3) GFRP stirrups spacing. The experimental results showed considerable enhancement in the shear capacity of the strengthened beams by 8 to 56% depending on the effectiveness of the studied parameters. Ductility and toughness were improved when more intensive strengthening schemes were adopted. The shear capacity of all tested beams based on Egyptian code ECP 208–2019 is calculated and compared with that from American code ACI 440–2019 and Canadian code CSA-A23.3-04. The shear capacity from both Egyptian and American codes compared with experimental loads. The analytical results are conservative in some cases and unconservative in others while the analytical results in general are conservative. The Canadian code CSA-A23.3-04 is unconservative compared to the experimental results for the range of the studied parameters and specimens.