Assembly Strength Tests of SB4-type Spring Clips

2021 ◽  
Vol 65 (190) ◽  
pp. 97-101
Author(s):  
Małgorzata Ostromęcka ◽  
Andrzej Aniszewicz
Keyword(s):  
Strength Test ◽  
Clamping Force ◽  
Strength Tests ◽  
Dimensional Measurements ◽  
Measurement Methodology

The article discusses the results of assembly strength tests carried out on SB4-type spring clips. Increases in the “b” and “f ” dimensions were observed and the tests were extended to include measurements performed after ten and fifteen assemblies and disassemblies of the spring clip. Special emphasis has been placed on the ability to interpret the obtained results of the clip’s measured clamping force in relation to the applied measurement methodology. Keywords: rail fastening, spring clip, dimensional measurements, assembly strength test, clamping force

Influence of the Applied Measurement Methodology on the Results of Geometric Measurements of the SB4 Spring Clips

2021 ◽  
Vol 65 (191) ◽  
pp. 89-93
Author(s):  
Małgorzata Ostromęcka ◽  
Andrzej Aniszewicz
Keyword(s):  
Base Plate ◽  
Measurement Methods ◽  
Clamping Force ◽  
Uncertainty Of Measurement ◽  
Dimensional Measurements ◽  
Measurement Methodology

The article presents the results of measurements of the “b” dimension of the SB4 spring clips carried out using three measurement methods that differ in the method and width of the base plate contact. The results obtained are presented and the uncertainty of measurement for each method is estimated. Attention was paid to the issues of the obtained dispersion of the value of the “b” dimension. The tolerated dimensions are discussed. The proposed measurement methods can help to identify shape mismatches of spring clips. Keywords: rail fastening, spring clip, dimensional measurements, clamping force

scholarly journals EARLY STRENGTH TESTING AFTER ACL RECONSTRUCTION IMPACTS ISOKINETIC STRENGTH PERFORMANCE AT TIME OF RETURN TO SPORT

2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0011
Author(s):  
Adam Weaver ◽  
Dylan Roman ◽  
Maua Mosha ◽  
Nicholas Giampetruzzi
Keyword(s):  
Test Performance ◽  
Knee Extension ◽  
Strength Test ◽  
Strength Testing ◽  
Isokinetic Strength ◽  
Rehabilitation Process ◽  
Strength Performance ◽  
Knee Extension Strength ◽  
Isometric Knee Extension ◽  
Strength Tests

Background: The standard of care in ACL reconstruction (ACLR) typically involves standardized strength testing at 6 months or later to assess a patient’s readiness to return to play (RTP) using isokinetic and isometric testing, and functional strength testing. Recent literature suggests that isokinetic knee extension strength should demonstrate 89% limb symmetry index (LSI) or greater prior to returning to sport. However, there is little known on the effects of strength testing early in the rehabilitation process and the relationship to strength test performance at time of RTP. Purpose: The purpose of this study was to examine how early post-operative strength test performance impacts isokinetic strength outcomes at RTP testing in adolescents. Methods: The retrospective cohort study included patients undergoing primary ACLR between 12 and 18 years of age, early post-operative strength measures, and isokinetic dynamometer strength at RTP from July 2017 and April 2019. Data was dichotomized into desired outcomes at 3 months: >70% isometric knee extension LSI, > 20 repetitions on anterior stepdown test (AST), > 90% LSI Y Balance. At RTP testing, isokinetic knee extension strength data was categorized into >89% LSI at 3 speeds (300, 180, 60°/sec). Chi square testing and odds ratio statistics were used to examine association and its magnitude. Results: 63 patients met inclusion criteria (38 females; 15.37±1.66 years old). >70% LSI isometric knee extension strength at 3 months showed a significant association (Table 2) and demonstrated the strongest odds of having >89% LSI on isokinetic strength tests at all 3 speeds at RTP with 180°/sec being the highest (OR=14.5; 95% CI=4.25,49.43; p= <0.001). Performance on AST showed a significant association (χ2 (1, n=63) = 17.00, p <0.001), and highest odds at 180°/sec (OR=4.61; 95% CI = 1.59, 13.39, p=<0.001) and 60°/sec (OR= 3.07; 95% CI = 1.10, 8.63, p= 0.04). Combination of performance on isometric strength tests and AST showed a significant association to isokinetic strength at all three speeds, but less predictive then isometrics in isolation. (Table 2). There was no significant relationship between YBR LSI at 3 months and isokinetic strength at 6 months. Conclusion: Standardized strength testing early in rehabilitation can help identify patients that will successfully complete RTP testing. Our results suggest that isometric knee extension strength and timed anterior stepdown test provide meaningful clinical information early in the rehabilitation process. This data also suggests that the use of YBAL for predicting isokinetic strength performance is limited. [Table: see text][Table: see text]

Assessment of post-heat behavior of cement mortar incorporating silica fume and granulated blast-furnace slag

2020 ◽  
Vol 11 (2) ◽  
pp. 221-246
Author(s):  
Ghasem Pachideh ◽  
Majid Gholhaki
Keyword(s):  
Tensile Strength ◽  
Flexural Strength ◽  
Blast Furnace Slag ◽  
Strength Test ◽  
Content Type ◽  
Granulated Blast Furnace Slag ◽  
Cement Mortars ◽  
Strength Tests ◽  
Pozzolanic Materials ◽  
Furnace Slag

Purpose With respect to the studies conducted so far and lack of researches on the post-heat behavior of cement mortars containing pozzolanic materials, the purpose of this paper is to investigate the post-heat mechanical characteristics (i.e. compressive, tensile and flexural strength) of cement mortars containing granulated blast-furnace slag (GBFS) and silica fume (SF). In doing so, selected temperatures include 25, 100, 250, 500, 700 and 9000c. Last, the X-ray diffraction test was conducted to study the microstructure of mixtures and subsequently, the results were presented as power-one mathematical relations. Design/methodology/approach Totally, 378 specimens were built to conduct flexural, compressive and tensile strength tests. Accordingly, these specimens include cubic and prismatic specimens with dimensions of 5 × 5 × 5 cm and 16 × 4 × 4 cm, respectively, to conduct compressive and flexural strength tests together with briquette specimen used for tensile strength test in which cement was replaced by 7, 14 and 21 per cent of SF and GBFS. To study the effect of temperature, the specimens were heated. In this respect, they were heated with a rate of 5°C/min and exposed to temperatures of 25 (ordinary temperature), 100, 250, 500, 700 and 900°C. Findings On the basis of the results, the most profound effect of using GBFS and SF, respectively, takes place in low (up to 250°C) and high (500°C and greater degrees) temperatures. Quantitatively, the compressive, tensile and flexural strengths were enhanced by 73 and 180 per cent, 45 and 100 per cent, 106 and 112 per cent, respectively, in low and high temperatures. In addition, as the temperature elevates, the particles of specimens containing SF and GBFS shrink less in size compared to the reference specimen. Originality/value The specimens were cured according to ASTMC192 after 28 days placement in the water basin. First, in compliance with what has been specified by the mix design, the mortar, including pozzolanic materials and superplasticizer, was prepared and then, the sampling procedure was conducted on cubic specimens with dimension of 5 × 5 × 5 mm for compressive strength test, prismatic specimens with dimensions of 16 × 4 × 4 mm for flexural strength test and last, briquette specimens were provided to conduct tensile strength tests (for each temperature and every test, three specimens were built).

An Analysis Model and its Practical Applications in PG&E Gas Transmission Pipeline Strength Test Projects

2018 ◽  
Author(s):  
Chunlei He ◽  
Edward Stracke
Keyword(s):  
Critical Role ◽  
Ideal Gas ◽  
Strength Test ◽  
Future Application ◽  
Test Duration ◽  
Test Medium ◽  
Analysis Model ◽  
Practical Applications ◽  
Pipeline Section ◽  
Strength Tests

This article presents a complete set of calculations (referred to as Model) PG&E developed to monitor, assess and approve strength tests on insitu (pipelines currently in service) gas transmission pipelines. How the Model is used in the field, 2017 test results, and process improvements that resulted from the implementation of the model are also discussed. In compliance with CPUC directives, the Code of Federal Regulations[1] and PG&E’s internal standards, PGE has performed strength tests on approximately 1,100 miles of insitu pipelines from 2011 through 2017. The model was specifically designed to assess the strength test of a closed section of gas pipeline for both leaks and ruptures. The model was originally designed for strength tests using water as the test medium and updated to accommodate nitrogen as a test medium. A future enhancement will be to incorporate a blend of Nitrogen and Helium as the test medium. The model plots the pressure-temperature and pressure-volume curves over the test duration (field test measurements) and compares them to the theoretically calculated curves. The curves are used to determine if the change in pressure is due to temperature influence or leakage. When water is the test medium, the model calculates the net corrected medium volume change from start to end of the static test period. When nitrogen is the test medium, the model calculates and analyzes net mass change of the medium by considering nitrogen under both the real gas state and the ideal gas state. By calculating restrained (buried) pipeline section and unrestrained (exposed) pipeline section separately, the model gains more accuracy. Accurate temperature measurements play a critical role in the model. The model makes it possible for engineers to monitor, analyze and direct strength tests with real-time test data. The model is also used to evaluate the pipeline fill condition on the day prior to the actual test, which resulted in fewer test restarts due to incomplete fill or temperature stabilization issues. An additional benefit is the tests were typically completed earlier in the day. The model is utilized on all PG&E insitu pipeline strength projects today. Authors also provide improvement suggestions of this model in future application.

Stability of an Aircraft Structure in a Strength Test Frame

1947 ◽  
Vol 51 (440) ◽  
pp. 704-714 ◽  
Author(s):  
P. B. Walker
Keyword(s):  
Structural Strength ◽  
General Rule ◽  
Strength Test ◽  
Strength Testing ◽  
Structural Failure ◽  
Considerable Time ◽  
Aircraft Structure ◽  
Strength Tests ◽  
Test Frame ◽  
Actual Test

The part played by major structural strength tests in aeroplane design is well known. Without such tests the standard of safety for aircraft would soon decline and excess weight, as an insurance against structural failure, would become a general rule. Considerable time and effort are expended therefore in the early stages of each new design of aeroplane to check by actual test whether its strength meets requirements. It is clearly reasonable to devote some little further time and effort to the study of methods and technique for strength testing in general.

Testing Aircraft to Destruction

1922 ◽  
Vol 26 (138) ◽  
pp. 195-230
Author(s):  
WM. D. Douglas
Keyword(s):  
Flight Test ◽  
Strength Test ◽  
General Description ◽  
Horizontal Force ◽  
Static Tests ◽  
Side Load ◽  
Historical Outline ◽  
Strength Tests ◽  
Loading Methods ◽  
Test Loading

Necessity for strength tests to supplement calculations and to check the assumptions on which the calculations are based. Historical outline. Examples of certain types of defect which are revealed by strength, test.Assumed aerodynamic conditions. Approximations reproduced by test loading. Methods of support during test. Measurements, testing routine and technique.The usual tests are described:—Flight test, C P . forward; Flight test, C P . back; Nose dive test; Tests of auxiliary and controlling surfaces; Ailerons, elevators and rudder; Tailplane and fins; Fuselage, down load, side load, torsion ; Undercarriage, discussion of stresses which may arise during landing, pointing out presence of frictional horizontal force causing rotational acceleration of the wheels; Static tests of undercarriages, dropping tests; General description of rib tests.Description of shot bags and general principles of load application with a view to efficiency and safety.

Proposal of Fire Resistant Composites with Application of Lightweight Aggregate Liaver

2014 ◽  
Vol 1054 ◽  
pp. 43-47 ◽  
Author(s):  
Marcel Jogl ◽  
Pavel Reiterman ◽  
Ondřej Holčapek ◽  
Jaroslava Koťátková
Keyword(s):  
Mechanical Properties ◽  
Lightweight Aggregate ◽  
Strength Test ◽  
Partial Replacement ◽  
Test Results ◽  
Standard Laboratory ◽  
Strength Tests ◽  
Hardened Properties ◽  
Brick Dust ◽  
High Temperature Effect

This paper describes the application of lightweight aggregate (LWA) in the creation of fire resistant composite. The effort of the project is the preparation of a light refractory material with good mechanical properties, which would reach technically economical solutions. We initially chose as lightweight aggregate Liaver, which in combination with chamotte aggregate represent the filler of composite. The following observations were focused on partial replacement of binding components with brick dust and its influence on the mechanical properties of the composite. After design process, test composite specimens were produced to determine hardened properties at standard age. On the 28 day were all the mixtures exposed to 105, 600 and 1000 °C. Lastly, the flexural and compressive strength tests were performed on the composite specimens to identify high temperature effect comparing to strength test results obtained from standard laboratory conditions.

scholarly journals AN INVESTIGATION OF THE STRUCTURAL STRENGTH OF TRANSTIBIAL SOCKETS FABRICATED USING CONVENTIONAL METHODS AND RAPID PROTOTYPING TECHNIQUES

2019 ◽  
Author(s):  
Brittany Pousett ◽  
Aimee Lizcano ◽  
Silvia Ursula Raschke
Keyword(s):  
3D Printing ◽  
Rapid Prototyping ◽  
Ultimate Strength ◽  
Stance Phase ◽  
Structural Strength ◽  
Static Strength ◽  
Strength Test ◽  
Manufacturing Method ◽  
Strength Tests ◽  
3D Printed

BACKGROUND: Rapid Prototyping is becoming an accessible manufacturing method but before clinical adoption can occur, the safety of treatments needs to be established. Previous studies have evaluated the static strength of traditional sockets using ultimate strength testing protocols outlined by the International Organization for Standardization (ISO). OBJECTIVE: To carry out a pilot test in which 3D printed sockets will be compared to traditionally fabricated sockets, by applying a static ultimate strength test. METHODOLOGY: 36 sockets were made from a mold of a transtibial socket shape,18 for cushion liners with a distal socket attachment block and 18 for locking liners with a distal 4-hole pattern. Of the 18 sockets, 6 were thermoplastic, 6 laminated composites & 6 3D printed Polylactic Acid. Sockets were aligned in standard bench alignment and placed in a testing jig that applied forces simulating individuals of different weight putting force through the socket both early and late in the stance phase. Ultimate strength tests were conducted in these conditions. If a setup passed the ultimate strength test, load was applied until failure. FINDINGS: All sockets made for cushion liners passed the strength tests, however failure levels and methods varied. For early stance, thermoplastic sockets yielded, laminated sockets cracked posteriorly, and 3D printed socket broke circumferen-tially. For late stance, 2/3 of the sockets failed at the pylon. Sockets made for locking liners passed the ultimate strength tests early in stance phase, however, none of the sockets passed for forces late in stance phase, all broke around the lock mechanism.  CONCLUSION: Thermoplastic, laminated and 3D printed sockets made for cushion liners passed the ultimate strength test protocol outlined by the ISO for forces applied statically in gait. This provides initial evidence that 3D printed sockets are statically safe to use on patients and quantifies the static strength of laminated and thermoplastic sockets. However, all set-ups of sockets made for locking liners failed at terminal stance. While further work is needed, this suggests that the distal reinforcement for thermoplastic, laminated and 3D printed sockets with distal cylindrical locks may need to be reconsidered. LAYMAN’S ABSTRACT 3D printing is a new manufacturing method that could be used to make prosthetic sockets (the part of the prosthesis connected to the individual). However, very little is known about the strength of 3D printed sockets and if they are safe to use. As Prosthetists are responsible for providing patients with safe treatments, the strength of 3D printed sockets needs to be established before they can be used in clinical practice. The strength of sockets made using current manufacturing methods was compared to those made using 3D printing. Strength was tested using the static portion of the ISO standard most applicable for this situation which outlines the forces a socket must take at 2 points in walking–when the foot is placed on the ground (early stance) and when the foot pushed off the ground (late stance). Sockets made for two prosthetic designs (cushion and locking) were tested to determine if one is safer than the other. All sockets made for cushion liners passed the standard for forces applied statically. However, different materials failed in different ways. At early stance, thermoplastic sockets yielded, laminated composite sockets cracked and 3D printed sockets broke circumferentially. At late stance other components failed 2/3 of the time before the sockets were affected. This provides initial evidence that sockets made for cushion liners are statically safe to use on patients. Sockets made for locking liners failed around the end, showing that 3D printing should not be used to create sockets with the design tested in this study. Article PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/31008/24937 How to Cite: Pousett B, Lizcano A, Raschke S.U. An investigation of the structural strength of transtibial sockets fabricated using conventional methods and rapid prototyping techniques. Canadian Prosthetics & Orthotics Journal. 2019; Volume2, Issue1, No.2. DOI: https://doi.org/10.33137/cpoj.v2i1.31008 CORRESPONDING AUTHORBrittany Pousett, BSc, MSc, Certified Prosthetist,Head of Research at Barber Prosthetics Clinic,540 SE Marine Dr, Vancouver, British Colombia V5X 2T4, Canada.Email: [email protected]

scholarly journals Effect of cementation on the mechanical behavior of a nanoceramic resin

Cerâmica ◽  
2020 ◽  
Vol 66 (379) ◽  
pp. 236-242 ◽  
Author(s):  
A. D. Nogueira ◽  
P. H. Corazza ◽  
O. E. Pecho ◽  
M. M. Perez ◽  
M. Borba
Keyword(s):  
Flexural Strength ◽  
Mechanical Behavior ◽  
Vickers Microhardness ◽  
Compressive Load ◽  
Strength Test ◽  
Load Test ◽  
Resin Cement ◽  
Restorative Material ◽  
Weibull Analysis ◽  
Strength Tests

Abstract Conventional flexural strength tests of restorative materials neglect the effect of essential variables that can affect their mechanical behavior. The purpose of this study was to evaluate the effect of cementation on the mechanical behavior of a nanoceramic resin. A nanoceramic resin (LU) and a leucite-reinforced glass-ceramic (IE) were evaluated. Non-cemented specimens of the materials were produced and subjected to biaxial flexural strength test ( σ f , n = 30 ). Cemented specimens were constituted of the restorative material bonded with resin cement onto a dentin analog substrate. Cemented specimens were subjected to the monotonic compressive load test ( L f , n = 20 ). Vickers microhardness (HV) and translucency parameter (TP) of the materials were characterized. Data were analyzed using t-test (σf and TP), Mann-Whitney test (Lf and HV), and Weibull analysis (σf and Lf, α = 0 . 05). Non-cemented LU showed higher σf and Weibull modulus (m) than IE. When cemented to the substrate, LU showed higher Lf than IE; however, the m-value was similar among groups. LU showed lower HV than IE and higher TP values. Cementation influenced the mechanical behavior and failure mode of the nanoceramic resin.

scholarly journals Changes in the Strength of the Polymer Concrete Used in the Electroplating Vats Under Operational Load

2017 ◽  
Vol 27 (4) ◽  
pp. 185-193
Author(s):  
Lidia Radna ◽  
Volodymyr Sakharov
Keyword(s):  
Strength Test ◽  
Polymer Concrete ◽  
Sustained Load ◽  
Copper Industry ◽  
Concrete Material ◽  
Operational Conditions ◽  
Tensile Strength Test ◽  
Operational Load ◽  
Strength Tests ◽  
Increased Strength

Abstract Due to the strong and aggressive electrolyte media and thermal load, design of the electroplating vats in the copper industry often relies on the resin concrete. The article presents the results of the strength tests of the polymer concrete based on the "Derakane" resin, used in the construction of electroplating vats. Samples were taken from the real vats - both new and 17-year old. Strength tests included compression and bending tensile strength test. To assess the effect of operational conditions the tests were performed on the same-age vats, some of which were never used while others were subjected to the operational load. During the operation, the vats sustained load of the anode and cathode weights, cyclic electrolyte loading with a temperatures up to 60°C. As a result, it was noted that the operational conditions led to the increased strength of the polymer concrete material.

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