Evaluation Of Impact Strength Research Articles

Evaluation of Impact Strength and Flexural Strength of Polyether Ether Ketone vs. Computer-Aided Design/Computer-Aided Manufacturing Polymethyl Methacrylate Denture Base Materials: An In-Vitro Study.

The objective is to comparatively assess the impact strength and flexural strength of polyether ether ketone (PEEK) vs. computer-aided design/computer-aided manufacturing (CAD/CAM) polymethyl methacrylate denture base material. A total of 90 samples were fabricated with traditional heat cure PMMA, PEEK, and CAD/CAM PMMA and divided into three groups of 30 samples each.The impact strength of all the samples was measured using an Izod impact tester with a pendulum in the air at 23±2°C. A three-point bending test was used in a Universal Testing Machine to assess the flexural strength of all the samples. The impact strength and flexural strength mean values were computed using a one-way ANOVA test. Impact strength and flexural strength of PEEK (IS=10.22±1.25 kJ/m2 and FS=120±8.0 MPa) is almost identical to CAD/CAM PMMA sample (IS=9.595±3.313 kJ/m2 and FS=118.11±5.00 MPa) whereas for conventional heat cure PMMA (IS=4.00±.011 kJ/m2 and FS=75.4±4.50 MPa) the values are least among the three. PEEK or CAD/CAM PMMA share almost identical and superior mechanical properties, and both can be used as better alternatives for complete denture fabrication rather than using conventional heat cure PMMA.

Self-healing and impact strength evaluation of bio-based lightweight aggregate composite: a smart material for sustainable construction

Self-healing and impact strength evaluation of bio-based lightweight aggregate composite: a smart material for sustainable construction

An Experimental Evaluation of Impact Strength of Fiber Reinfoced Concrete by using Drop Weight Test Method

Abstract: Using the Drop weight test method on slab panels with various types of fibre and their various proportions, this research examines the impact resistance of reinforced concrete's fibre resistance. The results of the IS drop weight test method, which measured the impact qualities of objects travelling at low and high speeds as well as the spilling and scabbing areas, are discussed in the current review study. The most frequently employed test. The results will be increases with the fibers added in percentages.

Comparative evaluation of impact strength of mechanically modified heat polymerized polymethyl methacrylate (PMMA) resin with addition of 0.5, 1, 2 wt% of silver nanoparticles (AgNPs): An in-vitro study.

Polymethyl methacrylate (PMMA) is one of the most widely used denture base material because of favorable esthetics and desirable characteristics such as easy handling. Acrylic resins, although, have some inherent disadvantages such as relatively poor physical and mechanical properties. The objective of the present study was to evaluate and compare the impact strength of unmodified and modified heat cure PMMA-based denture base material with addition of different concentrations of silver nanoparticles (AgNPs) (0.5, 1, 2 wt%). The present in-vitro study comprised of a total of 60 samples allocated to four groups with Group A samples consisting of heat cure acrylic resin without any modification (used as control); Group B samples consisting of heat cure acrylic resin modified with 0.5 wt% of AgNPs; and subsequently, Group C and Group D samples consisting of heat cure acrylic resin modified with 1 wt% and 2 wt% of AgNPs, respectively. The impact strength of the prepared acrylic samples was evaluated using Izod/Charpy Impact Tester, while the values obtained were tabulated and subjected to statistical analysis. Statistical analysis was done using Statistical Package for Social Sciences (SPSS) version 17.0 (SPSS Inc., Chicago, IL, USA), while one-way analysis of variance and Tukey's multiple post-hoc procedures were used for statistical analysis. P < .05 was considered statistically significant. The highest impact strength was found in Group C samples consisting of heat cure acrylic resin modified with 1 wt% of AgNPs to be closely followed by Group B samples consisting of heat cure acrylic resin modified with 0.5 wt% of AgNPs. Group D samples consisting of heat cure acrylic resin modified with 2 wt% of AgNPs, although, revealed relatively lower impact strength compared to Group B and Group C samples. Within the limitations of the present study, it was concluded that the impact strength of mechanically modified heat polymerized PMMA resin was significantly enhanced with addition of varying concentrations of AgNPs, although, it was observed that with an increase in the concentration of AgNPs, a subsequent decrease in the tensile strength of the final polymer material was observed.

Comparative evaluation of impact strength of natural tooth and two different fragment reattachment technique

Background: The reattached fragments are prone to re-fracture if another traumatic episode occurs or under non-physiological use of the restored teeth. There is a scarcity of literature regarding the management of uncomplicated crown fracture reattachment following a further fracture Therefore, concerns have been directed towards the strength of reattachment of the fractured teeth. Hence the aim of the in-vitro study was to evaluate &amp; compare the impact strength of reattached fragments with composite resin &amp; polyethylene fiber impregnated in composite resin with that of the natural tooth. Methodology: Total samples of 42 teeth were collected and indicated for extraction. They were cleaned ultrasonically and later stored in a 0.9% saline solution. The samples were divided into three groups of 14 samples each. The fracture was induced by disk, only Ellis class II fractured teeth were included in the study. Group 1 (control group) sound tooth: Directly checked for impact strength. Group 2: Reattachment of the fractured fragment using composite resin. Group 3: Reattachment using polyethylene fiber impregnated in composite resin with minimal preparation. All samples were thermocycled between 5°C - 55°C for 500 cycles with 30 seconds dwell time and tested in an ‘impact testing machine’.

Explosion Impact Strength Evaluation Technology and Safety Measures for Refrigerant Circuit Components.

The demands of heat cycles are increasing in the recent society where high performance of electronics or comfortability of our life are required. In order to use them safely and efficiently, the thermal accidents caused by high speed destruction or explosion have to be avoided. The usage of a pressure relief valve is one of effective measures. For an instance it can safely exhaust high-pressure combustible gas generated as a diesel engine like explodes in an air conditioner compressor. In this study histories of strain and pressure growing process that was referred as diesel explosion process in the compressor were estimated and measured. Then it was found that the pressure reached to a maximum at 4 msec after the valve was opened, due to the heat supply from the combustion gas inside the compressor, and that these phenomena induced the overshoot of valve pressure. These phenomena were estimated by analyses and experiments, it was found that this overpressure caused the delay of functional removement of the valve. Finally, these information were applied to product design, and these knowledges were able to avoid pressure vessel breakage.

EVALUATION OF IMPACT STRENGTH OF HEAT CURE ACRYLIC RESIN REINFORCED WITH NYLON FIBER MESH WITH AND WITHOUT PRESTRESSING (IN VITRO STUDY)

INTRODUCTION: Acrylic resin prostheses are liable to high levels of forces due to their frequent removal by patients and accidental slippage. Hence, the impact strength of acrylic denture base material is of major significance in providing long-term functional prostheses.OBJECTIVES: The aim of this study was to evaluate the reinforcing effect of prestressed nylon fiber meshwork and the specimen thickness increase on the impact strength of heat cure acrylic resin.MATERIALS AND METHODS: 72 specimens were divided into 3 groups (I, II and III) which were heat cure acrylic resin (control), Nylon mesh reinforced acrylic resin and prestressed-nylon mesh reinforced acrylic resin. Each group was formed of 24 specimens, which were further subdivided into 3 subgroups (A, B and C) of different dimensions; 75 mm × 10 mm × 3 mm and 75 × 10 × 4 mm and 75 x 10 x 5 mm. Thus, the specimens were divided into 9 experimental subgroups (n=8 per subgroup). A Charpy’s impact tester was used to measure the impact strength of acrylic resin. The data were analyzed using Anova-test (p≤0.05).RESULTS: The mean impact strength of groups II and III was higher than the control group I impact strength. The difference between the reinforced groups and control group was statistically significant for all specimen thicknesses.CONCLUSIONS: The impact strength of heat cure acrylic resin was increased by the incorporation of nylon fiber mesh whether prestressed or not.

Evaluation of Impact Strength of Silver Nano-Particles Reinforced Heat-Activated Polymethylmethacrylate (Pmma) Resin at Various Proportions

Evaluation of Impact Strength of Silver Nano-Particles Reinforced Heat-Activated Polymethylmethacrylate (Pmma) Resin at Various Proportions

Ergometric evaluation of impact strength that lead to skull fracture: features of individual methods, typical expert mistakes and methods of their prevention

Two current approaches to the ergometric evaluation of the impact strength that lead to skull fracture are described. Within each of them, the features of particular techniques, typical expert errors, ways and means of preventing them are analyzed. Quantitative data on the contribution of various initial parameters (fracture type, age, bone thickness, skull radius of curvature, body weight, height, etc.) to the result of computational diagnostics are presented.

Low- Velocity Impact Damage Observation and Compression After Impact Strength Evaluation of 3D Printed Continuous Carbon Fiber Reinforced Thermoplastic Laminates

Low- Velocity Impact Damage Observation and Compression After Impact Strength Evaluation of 3D Printed Continuous Carbon Fiber Reinforced Thermoplastic Laminates

Evaluation of Impact Strength and Surface Hardness of Acrylic Resin Modified with Different Nano Materials: An In Vitro Study

Evaluation of Impact Strength and Surface Hardness of Acrylic Resin Modified with Different Nano Materials: An In Vitro Study

Evaluation of Impact Strength of Dental Acrylic Resins by Incorporation of TiO2 Nanoparticles Using Two Different Processing Techniques

The present study aims to evaluate the impact strength of PMMA incorporated with TiO2 nanoparticles by two different processing techniques i.e. water bath and microwave processing techniques. A total of 80 samples made of PMMA were divided into four groups. Each group includes 20 samples with group I and II comprising of samples made of normal acrylic resin and acrylic resin reinforced with 1 wt% TiO2 nanoparticles processed with conventional water bath technique respectively, groups III and IV include normal acrylic resin and acrylic resin reinforced with 1 wt% TiO2 processed using microwave technique respectively. The specimens were tested for impact strength using IZOD pendulum impact tester. The impact energy values obtained were analyzed statistically. The results through one-way ANOVA showed a high mean impact strength with group IV samples (23.13) and lowest with respect to group I (19.42) with highest statistical significance (p < 0.001). A post hoc Tukey test intergroup analysis showed a statistically significant difference between group I and other groups, whereas there was no statistical significance associated with other intergroup comparisons. PMMA with its current drawbacks in the physical and mechanical properties requires modifications to make it an ideal denture base material. The current investigation evaluates that a high mean impact strength with samples made of PMMA incorporated with TiO2 nanoparticles processed by microwave technique was obtained when compared with normal acrylic resins processed by water bath technique. The methodology of current study can be used while processing of denture bases for patients to evaluate the effect of oral environment on inclusion of TiO2 nanoparticles with microwave processing in a clinical setup. This could help in reducing the amount of fractures associated with heavy load masticatory stresses and improving the mechanical properties in denture bases. How to cite this article: Kumar CA, Kumar CR, Vamshikiran K, et al. Evaluation of Impact Strength of Dental Acrylic Resins by Incorporation of TiO2 Nanoparticles Using Two Different Processing Techniques. J Contemp Dent Pract 2019;20(10):1184-1189.

Effect of Copper and Magnesium Stoichiometric Additions and Thermal Aging on the Mechanical Properties of Cast Aluminium Alloys

Objective: To study the mechanical properties of newly developed cast aluminium alloy with additions of copper and magnesium in the mole ratio of 1:1:1 of Al-Cu-Mg in as cast and thermally aged conditions. Methods/Statistical Analysis: For the (wt.%) selection of Cu-Mg on the basis of stoichiometric calculations, 1 unit (wt.%) of copper and 1 unit (wt. %) of magnesium were mixed in base metal liquid. Aluminium 6063 base material was heated in an electric furnace at 750°C in permanent mild steel mould preheated at 200°C in order to achieve homogenised cast alloyed ingot. Findings: The specimens were extracted from cast aluminium ingot for tensile and impact strength evaluation, microhardness variations and metallurgical studies in as cast and aged conditions (160°C for 5,6 and 7 hours respectively). Optical microscopy reveals increased rate of intermetallic precipitation at aged conditions which was supported by X-ray diffraction patterns. Moreover, copper and magnesium additions increased the ultimate tensile strength, impact strength and microhardness values of newly developed aluminium cast alloy in comparison with conventional Al 6063 base material. Application/ Improvement: Therefore, based upon the present work, it is recommended to use this ratio of copper and magnesium in aluminium base alloy in order to achieve better mechanical properties in industrial applications. Keywords: Aluminum Alloys, Electric Furnace, Intermetallic Compounds, Solution Treatment, Thermal Aging

Evaluation of Impact Strength of Epoxy Based Hybrid Composites Reinforced with E-Glass/Kevlar 49

Evaluation of Impact Strength of Epoxy Based Hybrid Composites Reinforced with E-Glass/Kevlar 49

The Structure and Properties of the Samples Produced by Selective Laser Melting of 410L Steel-based Metal Powder

Additive technologies, which obtained the wide spreading in the last decade, allow producing items of any shape from metal materials practically without additional mechanical treatment. This approach based on the layer by layer melting of powder material accordingly to the premade 3D-CAD model, provides the geometrical accuracy which mostly depends on the size of the used material. In the present study, as material a 410 L steel powder was chosen, for which the basic dependencies between the selective laser melting (SLM) parameters and the mechanical properties were determined. Trial batches of standard samples for uniaxial tension and impact strength tests (according to the ASTM A370 and ASTM E8M standards) were produced. It was shown that in the as build (after SLM) the fracture appeared to be brittle with the impact strength 3-5J/cm2. The carried out heat treatment of quenching-tempering cycle and subsequent tests provide the viscous fracture and evaluation of impact strength up to 20-30J/cm2. Presumably, this is due to a refinement of the grain structure and the inner stresses reduction of the samples, which also acknowledges the execution EBSD analysis, which points to the presence of quenched and tempered martensite. The presence of high inner stresses can be attributed to two α-γ-α transformations that were revealed by dilatometry investigation. In the range of cooling or heating rates from 1 to 500°C/s temperatures of phase transformation are shifted.

Evaluation of the mechanical properties of high impact denture base resin with different polymer to monomer ratios: An In vitro study

Aim: This study aims to evaluate the flexural strength, hardness, and impact strength of heat-cured high-impact denture base resins with different polymer/monomer ratios. Materials and Methods: A total of 150 acrylic samples were prepared using high impact denture base resin (Travelon Hi). The samples were divided into five groups based on different powder/liquid ratios (g/ml) with 30 samples in each group. The P/L ratio in Group 1 (Ratio - 2.2:1) was the manufacturer's recommended ratio and was used as control. In Group 2, the ratio was 2.7:1, in Group 3, the ratio was 3.2:1, in Group 4, the ratio was 1.9:1, and Group 5 the ratio was 1.6:1. Each group with 30 samples was further subdivided into three different subgroups comprising 10 samples each, based on the properties to be evaluated, i.e., for flexural strength, hardness, and impact strength evaluation. The samples were tested for flexural strength, Vicker's hardness number (VHN) and impact strength. One-way ANOVA including post hoc-Tukey's tests was used to calculate the difference of means for quantitative variables and for intergroup comparison as well. Results: The results showed that the flexural strength values and VHN values showed a similar trend. The values decreased significantly as the ratio was increased or decreased from the control group. The results also showed that there was nonsignificant difference between the mean impact strength values for all the groups. Conclusion: For reinforced resins or high impact resins, the manufacturer's recommended polymer/monomer mixing ratio should be used to obtain the appropriate strength of the material.

Comparative Evaluation of Impact Strength of Dissimilar Metal Weld between T91 and 304SS Prepared by SMAW and GTAW Techniques

Objectives: The main objective was to evaluate the better joint between dissimilar metals T91 (ferritic) and 304SS (austenitic) prepared by SMAW and GTAW in accordance to their impact strength. Methods/Statistical Analysis: Welding joints between T91 and 304SS were developed using two welding consumables 308L and 309L by SMAW and GTAW respectively. 4 plates of dimension 175mm x 100mm x 6mm were used for welding each of 304SS and T91. Total 9 specimens were prepared according to ASTM A370 standards (55mmX10mmX6mm) for Charpy impact testing, three each from weld bead, HAZ 304SS and HAZ T91 each from SMAW and GTAW welded plates. Findings: Impact strength testing was done with help of Charpy V-notch toughness machine. The standard specimens for Charpy impact testing was placed in the machine and values of impact strength were recorded one after another. As per results, the average impact strength of the weldment prepared by GTAW technique is marginally more as compared to SMAW technique for all sections. The impact strength of the GTAW specimen increases from 304SS HAZ to T91 HAZ passing through the weld metal. The best impact strength is obtained at T91 HAZ of GTAW joint which is 232.67 joules. This increased value of impact strength may be due to movement of carbon particles and formation of carbides and intermetallic. The enhancement in the impact strength is encountered due to increase in micro-hardness which is also published by various authors in the characterization of the weldments. The average impact strength of the weldment prepared by GTAW technique is more as compared to SMAW technique. The dissimilar metal joint prepared by GTAW technique is better joint in accordance to its impact strength. Improvement/Applications: Dissimilar metal joints between austenitic stainless steel and ferritic stainless steel are widely used in various fields like nuclear power plants, steam generators of power plants etc.Keywords: Dissimilar Metal Welding, Gas Tungsten Arc Welding (GTAW), Impact Toughness Comparison, Shielded Metal Arc Welding (SMAW)

Explanation of impact load curve in ball impact test in relation to thermal aging

Solder joints are required to have high impact strength for use in portable electronic products. To make solder joints with high impact strength, qualitative evaluation methods of impact strength are required. Ball impact tests have been widely adopted in evaluating the impact strength of solder joints because of their easy implementation. Impact load curves obtained from ball impact tests are used as an evaluation indicator of impact strength of solder joint. However, a relation between fracture behavior and impact load curve has not yet been clarified, and an explanation of the impact load curve has not yet been provided in detail. In addition to this, detailed study about the relation between IMC layer thickness and impact strength has not been performed, although the IMC layer thickness formed at the interface would significantly affect the impact strength of the solder joint. This study aimed to explain the impact load curve in the ball impact test and to reveal the effect of the IMC layer thickness on the impact strength of the solder joint. Sn–3.0Ag–0.5Cu solder was reflowed on an electroless Ni–P plated Cu substrate (Ni–P), and a ball impact test was then carried out to evaluate the impact strength. This study found that the ball impact test is effective to evaluate the interfacial strength of solder joints. In the impact load curve, it is estimated that the solder bump keeps deforming until the interfacial crack initiates (maximum load), and the interfacial crack initiates after the maximum load and propagates along the interface between the solder and Ni–P. The suitable evaluation of impact strength became possible by measuring the correspondence relation between the deformation distance of the solder bump after fracture and the energy until maximum load and the relation between the area fraction of the residual solder on the fractured pad and the energy after maximum load. And, it is proved that the impact strength decreased with increasing aging time because the growth of the IMC layer remarkably degraded the interfacial strength of the solder joint.

OS1920 飛散防止フィルムを貼付したガラスの耐衝撃性評価

OS1920 飛散防止フィルムを貼付したガラスの耐衝撃性評価

The embrittlement mechanism and improvement of impact strength for lead-free solder joints in BGA packaging using electrolytic Ni/Au plating

Impact strength evaluation and fracture mechanism analysis in board level of Sn–3mass%Ag–0.5mass%Cu solder joints of ball grid arrays (BGA) using electrolytic Ni/Au plating were performed. The cause of impact strength degradation of BGA solder ball joints is the existence of low density defects, which contain organic materials, in the (Cu,Ni)6Sn5 intermetallic compound grain boundary formed in the solder joints. These organic materials are taken in by the nickel plating film at the time of nickel plating. To improve the impact strength of the Sn–3mass%Ag–0.5mass%Cu solder joint of the BGA, it is necessary to lower the concentration of these organic materials. The contamination prevention and nickel plating bath sanitization, solder mask material selection (to minimize nickel plating bath contamination) and higher current density of nickel plating are effective to keep a lower concentration of organic materials in nickel plating film.