Strength Testing Of Materials Research Articles

Experimental study on layer bonding property of 3D printing building materials

Bonding properties between 3D printing building materials layers are tested, including tensile strength test, shear strength and bending strength test of 3D printing building materials. The failure process and failure modes of 3D printing building materials are focused on analysis in this paper. Experimental results indicate that there are weak adhesive layers in the 3D printing building materials, specimen failure occurs in the weak adhesive layer. The tensile strength average value of 3D printing building materials is 0.74N/mm2. The shear failure of 3D printing specimen is not occurred, but bending failure. The bending strength average value of 3D printing building materials is 0.88N/mm2.

APPLICATION OF STRESS WAVES EMISSION FOR DETERMINATION OF FATIGUE CHARACTERISTICS OF MATERIAL

Results of experimental evaluation of the fatigue characteristics of tested samples material are considered based on emission of stress waves. Using previously published data on synergistically organized acoustic emission, an experiment was prepared and performed. In experiments on different materials, possibility of using acoustic emission signal for operative determination of mechanical characteristics and, above all, the limit of endurance were demonstrated. Samples for strength testing of materials were made of five steel grades and one grade of Br AZh9-4 bronze. Five experiments were conducted on each of the materials. The samples in the experiment underwent a fine-step loading, at each step of it radiation of signal occurred simultaneously, and another series of dislocations was prepared, that could reach surface of crystal and emit a stress wave at the next moment of loading. Thus, the joint radiation of energy dislocations prepared for movement was already formed. A comparison of experimental data, obtained on the basis of acoustic emission, with calculated values of endurance limit, obtained by empirical formulas through the ultimate strength of this material, performed by the Fisher criterion, has shown their adequacy at a significance level of 5 %. Evaluation of the experimental results of endurance limit determination on basis of acoustic emission by the Cochran test indicates that variances of measurement results in experiment are uniform for all types of used materials. The results have shown that such method on the basis of synergistically organized acoustic emission allows us to quickly obtain experimental values of endurance limit of material with sufficiently high degree of accuracy.

Evaluation of Geotechnical Properties of Sub-Grade Material Used in Road Construction

The aim of this research is evaluation of geotechnical properties of sub grade material used in Bukur-Setera road construction. Tests conducted in laboratory for gravel material are grain size analysis, atterberg limit, free swell, maximum dry density and optimum moisture content. The material strength test was conducted interms of California bearing ratio. Because of less finer materials, the percentage of swelling is low. Gravel materials involved in this investigation have taken a larger CBR value of 21% for 5mm penetration. According to ERA 2013 manual, the materials having good to excellent subgrade materials, having CBR value greater than or equal to 30%. But the actual values are less than 30%. Accordingly, it has a limitation of using the material as sub grade materials. Keywords : Laboratory test, Sub grade, California Bearing Ratio DOI : 10.7176/CER/11-1-04

STRENGTH CONTROL SYSTEM UNDER DYNAMIC LOAD WITH ELECTROMAGNETIC ACCELERATOR

The article describes the device to control the strength of brittle materials under dynamic load. A design was developed and an electromagnetic accelerator was manufactured. It allows to perform mechanical strength tests of brittle materials at speeds up to 10 m/s. It was defined that the device on the basis of the Hopkinson measuring cores can also be used while studying the energy characteristics of the solid alloys destruction and the investigation of the cutting process. The obtained experimental results on the strength of solid alloys can be used to predict the probability of incisors destruction.

Sandwich Panel Manufacturing Method In Form of Test Specimens For Ship Construction

Sandwich panel as a composite materials require special method of manufacture, to produce the best of physical condition. This study give the manufacturing process of sandwich panel for the purpose of testing the strength of material. Sandwich panel created with molding method for simplify the process of work and can be repeated if a failure occurs. Saveral failures occur in creating process until preparation specimen process that are influenced by saveral things, such as damage caused by the temperature of the sun, difference in viscosity between the layers of the conditions faceplate (smooth and rough), and the method of cutting the sandwich panel which requires cutting methods at low temperatures and does not produce the high vibration to avoid damage to the material before material strength test were performed.

Pengaruh Radiasi Neutron Terhadap Waktu Relaksasi Spin-Kisi (T1) Pada Polimer Polivinil Klorida (Pvc) dengan Spektroskopi Nmr Pulsa

A research measurement of spin-lattice relaxation time (T1) with a pulse NMR spectrometer as well as a test of strength (tensile test and compression test) polymer material PVC (Poly Vinyl Chloride) with tools united-1 test system SFM SFM-30. The study aims to investigate the influence of the neutron fluence on the spin-lattice relaxation time (T1) and to determine the PVC polymer material strength test. On the measurement of the spin-lattice relaxation time (T1) is used method pulse 180o-t-90o and pulse method 90o-t-90o, by means of NMR minispec P.20. Measurement of PVC polymer material strength testing using tools united-1 test system SFM SFM-30. The results showed that the spin-lattice relaxation time (T1) PVC polymer influenced by variations in relaxation times (fluence) neutrons. From the graph of the spin-lattice relaxation time (T1) vs. neutron fluence with the method 90o-t-90o obtained increases and decreases in the value of T1. The value of the spin-lattice relaxation time at the minimum fluence 34.56x1016n/cm2, and the average value of the minimum T1 is (271.1±5.4) for the milli second pulse method 180o-t-90o and the average value The minimum T1 is (263.5±5.3) for the milli second pulse method 90o-t-90o. The value of the spin-lattice relaxation time at the maximum fluence 60.98 x 1016 n/cm2, the average value of the minimum T1 was (481.9±10.1) milli second to the method also 180o-t-90o and the average value of T1 The minimum was (482.5±9.7) for the milli second pulse method 90o-t-90o. Test the strength of the PVC polymer is affected by the neutron fluence. Graph PVC polymer material strength test vs. neutron fluence obtained increases and decreases in the value of the strength of the PVC polymer. Value of the minimum strength of the PVC polymer materials at fluence 34.56 x 1016 n/cm2, the average value of the minimum σ is (9.5± 0.1) MPa for tensile test, and the average value is the minimum σ (38.4±0.1) MPa for compression test. Value of the maximum power of the PVC polymer materials at fluence 60.98x1016n/cm2, the average value of the maximum σ is (43.2±0.9) MPa for tensile test and the average value of the maximum σ is (55.4±1.1) MPa for compression test.

Flexural Strength Tests of Brittle Materials: Selecting the Number of Specimens and Determining Confidence Limits for Weibull Parameters

Abstract The flexural strength of brittle materials has been found to follow the two-parameter Weibull distribution. This paper describes a simple method of estimating the Weibull modulus and characteristic strength that allows for the computation of confidence intervals that will contain the true values within a specifiable level of confidence. The sample size needed to meet the experimenter's precision requirements is determined. A sample of flexural strength data from the literature is used to illustrate all of the computations. The precision of the method is compared to that of the method of maximum likelihood. It is found to be inferior to maximum likelihood for estimating the Weibull modulus but quite comparable for estimating the scale parameter.

The tensile strength test of thermoplastic materials based on poly(butylene terephtalate)

Thermoplastic composites go toward making an increasingly greater percentage of all manufacturing polymer composites. They have a lot of beneficial properties and their manufacturing using injecting and extrusion methods is a very easy and cheap process. Their properties significantly overtake the properties of traditional materials and it is the reason for their use. Scientists are continuously carrying out research to find new applications of composites materials in new industries, not only in the automotive or aircraft industry. When thermoplastic composites are manufactured a very important factor is the appropriate accommodation of tensile strength to their predestination. Scientists need to know the behaviour of these materials during the impact of different forces, and the factors of working in normal conditions too. The main aim of this article was macroscopic and microscopic analysis of the structure of thermoplastic composites after static tensile strength test. Materials which were analysed were thermoplastic materials which have poly(butylene terephthalate) – PBT matrix reinforced with different content glass fibres – from 10% for 30%. In addition, research showed the necessary force to receive fracture and set their distinguishing characteristic down.

Effect of plasma treatment in Aluminum and composites bonding joints: Shear load tests results

This paper presents the results of simple adhesive lap joint shear strength tests of materials under atmospheric plasma treatment conditions. The effects of surface activation of the shear joint by cold atmospheric plasma in the perspective of the adhesion promotion are discussed. Specifically, the changes in the maximum strength introduced by the plasma of coupon samples of aluminum and carbon fiber reinforced materials. Finally, the results of tests and some conclusions are reported.

Universal Data Acquisition and Control System for Strength and Thermomechanical Tests of Materials and Structure Elements

A universal GDS-16 data acquisition and control system based on Quantum X MX840 measuring amplifiers and Catman Easy software is described. The system provides multichannel measurements of strains, displacements, pressures, and temperatures, data processing, visualization, and accumulation, which permits strength and thermomechanical tests of materials and structure elements to be performed.

A systematic design approach of an embedded-control material-strength testing system

In this paper, an embedded control system is developed to measure the yield strength of the material plate with an applied load. A systematic approach is proposed to handle special requirements of embedded control systems, which are different from computer-based control systems, as there are much less hardware resources and computational power available. An efficient control algorithm has to be designed to remove the CPU burden so that the microcontroller has enough power available. A three-step approach is proposed to address the embedded control issue: firstly, the mathematical description of the whole system is studied using both theoretical and experimental methods. A mathematical model is derived from the physical models of each component used, and an experiment is retrieved by employing Levy’s method and least-square estimation to identify specific parameters of the system model. Secondly, a feedforward plus feedback controller is designed and simulated as a preparation for the embedded system implementation. The cerebellar model articulation controller (CMAC) is chosen as the feedforward part, and a PD controller is used as the feedback part to train the CMAC. Finally, the proposed algorithm is applied in the embedded system, and experiments are conducted to verify both the identified model and designed controller.

Experimental research of masonry compressive strength in the Auschwitz II - Birkenau former death camp buildings

Abstract The paper presents the results of strength tests of brick masonry in 14 prisoner barracks located at the Auschwitz II-Birkenau former death camp. These buildings were constructed in a few months in 1941, that is in the initial phase of the extermination camp. Strength tests were conducted as part of a broad program whose purpose was to document the condition of the camp buildings being invaluable historical material objects. Due to the nature of the historical buildings a broad program has been consulted with the services of conservation. Strength tests of masonry and masonry materials (bricks and mortars) were performed on small-diameter core samples cut from the original structures of buildings in the camp. In addition, comparative tests were carried out on samples made in the laboratory. Results and their analysis made it possible to estimate the compressive strength of masonry, bricks and mortars in the brick buildings erected more than 70 years ago. The performed documentation of brick walls and identification of strength parameters are an important stage of the planned preservation process, the ultimate goal is to preserve the historic buildings for future generations.

Reason analysis and treatment for concrete material cracks of tunnel lining

In the construction of highway tunnels, the lining material is mainly composed of reinforced concrete. However, this lining concrete will crack if it does not have sufficient strength. Such cracks will aggravate internal reinforced material rust, impacting the tunnel's safety and waterproofness. Once a highway tunnel has been in operation for 2 years, cracks become apparent. To assess the cracks, highway tunnel construction was investigated, and the causes were analysed on convergence of tunnel section, material strength test and numerical simulation. Possible factors in the design, construction and operation stages were also researched, such as partial pressure; material strength and engineering geology. The concept of quality management in the whole process is proposed. In addition, it is crucial to choose the appropriate materials to reinforce in a timely manner, to avoid too much cracking and ensure long-term stability. The research results have great significance for the safety control and management of highway tunnels.

Elastoplastic properties of microand submicrocrystalline metals and alloys

The problem of application of physical acoustic methods to studying the mechanisms that control plastic deformation and fracture is considered using micro- and submicrocrystalline materials (Be, Al, Ti, Al–Sc alloy, Cu–Nb laminated material) as examples. The influence of grain boundaries on the acoustic (elastic, inelastic) properties of polycrystalline micro- and nanostructured metallic materials is analyzed. Experimental results are presented for a wide oscillating-stress amplitude range, from 0.2 to 50 MPa. The experimental data are discussed in terms of the theoretical concepts of oscillatory dislocation mobility, which depends on both the short-range stress fields around point defects and the long-range fields of internal stresses. It is shown that various types of discontinuities, such as pores and microcracks, noticeably influence the acoustic properties. The aspects of the relation, similarity, and difference between acoustic and mechanical (plasticity, strength) tests of polycrystalline materials with micro- and nanosized structural elements are discussed.

Effect of an experimental silica-nylon reinforcement on the fracture load and flexural strength of bisacrylic interim partial fixed dental prostheses

Statement of the problemMaterials used in the fabrication of interim restorations usually have mechanical properties inferior to those used in definitive prostheses. Various techniques may be used to reinforce these materials. PurposeThe purpose of this in vitro study was to evaluate the fracture strength of interim partial fixed dental prostheses (FDPs) with and without an experimental silica-nylon reinforcement placed in different orientations (horizontal or vertical) before and after thermocycling and to evaluate the flexural strength of the bisacrylic resin used for fabricating these prostheses. Material and methodsFor fracture strength testing, 72 four-unit interim partial FDPs were fabricated from bisacrylic resin and divided into 3 groups: no reinforcement, horizontal reinforcement, and vertical reinforcement. Half of the specimens from each group were thermocycled before testing (1000 cycles between 5°C and 55°C) (n=12). An increasing load was applied to the center of the prosthesis until fracture. The flexural strength of bisacrylic resin reinforced with the experimental mesh was measured by using a 3-point bending test with 25×10.5×3.3 mm bars of resin, with or without thermocycling. The results were evaluated with analysis of variance and Kaplan-Meier survival analysis (α=.05). ResultsThe results showed that incorporating the experimental silica-nylon reinforcement in a horizontal orientation provided the highest values of fracture strength for the 4-unit partial FDPs. Reinforcement also enhanced the flexural strength values of bisacrylic resin bars. ConclusionSilica-nylon reinforcement is an effective method of increasing the strength of interim restorations.

Automation of Universal Testing machine using Human Machine Interface (HMI)

In the material strength test, stress and strain rate are often required to be constant. For example, during the cement quali ty inspection, the loading rate is required to be2.4 ± 0.2KN/S (1); when measuring the upper and lower yielding points of metallic materials, the stain rate should stay between 0.00025/S and 0.0025/S; In the determination of elongation at break, the stress rate should stay in the r ange of 1-10N/mm 2 S -1 when the elasticity modulus smaller than 150000 N/mm2 (2). Since 1950s, Material Testing Machines, which adopted large-flow electro- hydraulic servo, valve to form control system, have appeared in developed countries. Control system of this type could meet the requirements for the stress and strain rate in the material strength test. For example, MTS and Instron from USA, Schench from German, and Shimadzu from Japan all adopted this type of system. With the improvement of the manufacturing level of proportional valve and the development of control technology, electro-hydraulic proportional valve began to be used as the main control part home and abroad (4). However, this type of parts, which is vulnerable to pollution, requires medium of high cleanliness. It is of large noise and high price. This type of system could go wrong easily for the complex hydraulic system. Universal Testing Machine is used for several advanced applications like checking tensile as well as compressive strength of materials to be used to build any kind of physical system .Based on this proposes a simple and effective control system, which has a good control effect upon stress rate and strain rate in the application of engineering practice .This type of system can be used in various strength testing device. Test and inspection show that this system, which totally meets the loading requirements of stress rate or strain rate in the national standards, can be used in hydraulic testing machines (7). The new compact touch screen panel has been presented and implemented successfully by embedded system technology with the current system. So that the most advanced touch screen panel provide clear analytical treatment for load v/s elongation curves, values of stress & strain coming from different channels. The touch screen should also be well- suited in terms of cost, size, smoothness and ease of integration in the circuit boards of measuring devices. II. Methodology:

Tensile Strength and Flexural Strength Testing of Acrylonitrile Butadiene Styrene (ABS) Materials for Biomimetic Robotic Applications

Biomimetic robots borrow their structure, senses and behavior from animals, such as humans or insects, and plants. Biomimetic design is design ofa machine, a robot or a system in engineeringdomain thatmimics operational and/orbehavioral model of a biological system in nature. 3D printing technology has another name as rapid prototyping technology. Currently it is being developed fastly and widely and is applied in many fields like the jewelry, footwear, industrial design, architecture, engineering and construction, automotive, aerospace, dental and medical industry, education, geographic information system, civil engineering, guns. 3D printing technology is able to manufacture complicated, sophisticated details that the traditional processing method cannot manufacture. Therefore, 3D printing technology can be seen as an effective tool in biomimetic, which can accurately simulate most of the biological structure. Fused Deposition Modeling (FDM) is a technology of the typical rapid prototyping. The main content of the article is the focusing on tensile strength test of the ABS-Acrylonitrile Butadiene Styrene material after using Fused Deposition Modeling (FDM) technology, concretization after it’s printed by UP2! 3D printer. The article focuses on two basic features which are Tensile Strength and Determination of flexural properties.

Interface Shear Strength Testing of Geogrid-Reinforced Construction and Demolition Materials

Abstract The interface shear strength properties of geogrid-reinforced recycled construction and demolition (C&D) materials were determined in this research to assess the viability of using geogrid-reinforced C&D materials as alternative construction materials. The C&D materials investigated were recycled concrete aggregate (RCA), crushed brick (CB), and reclaimed asphalt pavement (RAP). Biaxial and triaxial geogrids were tested as the geogrid-reinforcement materials. The interface shear strength properties of the C&D materials were ascertained by using a large direct shear test (DST) equipment. Large-scale DST was conducted for unreinforced and geogrid-reinforced C&D materials. The interface peak and residual shear strength property of unreinforced and geogrid-reinforced RCA was found to be higher than that of CB and RAP. RAP was found to have the lowest interface shear strength properties of the C&D materials. The higher strength triaxial geogrids were found to attain higher interface shear strength properties than that of the lower strength biaxial geogrids. The DST results, however, indicated that the interface shear strength properties of the geogrid-reinforced C&D materials were less than that of the respective material without reinforcement. This can be attributed to the lack of interlock between the geogrids and the recycled C&D aggregates, as well as the current conventional testing method for DST that induces a shear plane at the boundary between the lower and upper boxes where the geogrid is placed. The unreinforced and geogrid-reinforced RCA, CB, and RAP were found to meet the peak and residual shear strength requirements for typical construction materials in civil engineering applications.

The Hollowing Test Method Research in Constructional Floor and Decoration Projects

The constructional decoration and constructional flooring projects are the important parts in constructional engineering and currently the qualities of face tile attachment and plaster layer adhering are checked by means of visual observation and gentle knocking with small hammer after the end of project. However, the said conventional visual observation and knocking test methods are more in subjective randomness and low in efficiency to result in poor inspection effect. With the principle of the rebound value being abnormally quite low in case there are air holes or hollowing in the process of compressive strength test of materials with rebound method, the hollowing defect distributions in constructional flooring and architectural decoration engineering can be detected completely, accurately and visually by means of reasonable test point layout and effective defaults judgments.

Remodeling of Extracellular Matrix Patch used for Carotid Artery Repair

We evaluated the in vitro strength and in vivo arterial-wall response to an extracellular-matrix-based patch material in a sheep model of carotid artery repair. A six-ply sheet of acellular, porcine extracellular matrix (ECM) was subjected to in vitro material strength testing and implanted in 15 sheep for 30, 90, and 180 d. Bovine pericardium was used as a control in some animals. In vivo graft patency was assessed by angiography. Explanted grafts were evaluated by histopathology and burst-strength testing. Mean (SD) in vitro suture retention force of the ECM sheet was 14.5 (3.06) N; tensile strength was 29.7 (6.11) N; and probe burst strength was 185 (22.6) N. In vivo, mild stenosis was observed at 30 d for all patches; stenosis was absent at 90 d in the ECM-repaired arteries but not bovine pericardium controls. Pseudoaneurysm was not observed in any animal. Histopathology showed progressive graft degradation, collagen deposition, formation of neocapillaries and fibrocellular neointima, and endothelialization, but no calcification. Mean (SD) burst pressure for unrepaired arteries was 2608 (858) mmHg and 1473 (694) mmHg for ECM-repaired vessels. Mean change in diameter from unloaded state to burst pressure was 29% (9.7) for unrepaired vessels and 24% (13.4) for ECM-repaired vessels. The six-ply ECM sheet can withstand the forces encountered after carotid artery repair. In sheep, it shows evidence of progressive, constructive remodeling as early as 30 d post-implantation with rapid deposition of endothelium. ECM shows promise as a patch material for CEA repair.