A Study on Differences of Resultant Forces of Jiji by Hapchung in Myeongrihak

In concrete box girders, the amount and distribution of reinforcements in the webs have to be estimated considering the local effects due to eccentric external loads and cross-sectional distortion and not only the global effect due to the resultant forces of a longitudinal analysis: shear, torsion and bending. This work presents an analytical model that allows designers to take into account the interaction of all these effects, global and local, for the determination of the reinforcements. The model is based on the theory of stress fields and it has been compared to a 3D finite element analysis, in order to validate the interaction domains. The results show how the proposed analytical model allows an easy and reliable reinforcement evaluation, in agreement with a more refined 3D analysis but with a reduced computational burden.

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Transducer-based comparisons of the prosthetic feet used by transtibial amputees for different walking activities: a pilot study

Prosthetics and Orthotics International ◽

10.1177/0309364612436408 ◽

2012 ◽

Vol 36 (2) ◽

pp. 203-216 ◽

Cited By ~ 21

Author(s):

Edward Schreiber Neumann ◽

Kartheek Yalamanchili ◽

Justin Brink ◽

Joon S Lee

Keyword(s):

Clinical Decision Making ◽

Research Question ◽

Case Series ◽

Clinical Decision ◽

Residual Limb ◽

Convenience Sample ◽

Loading Patterns ◽

Prosthetic Feet ◽

Transtibial Amputees ◽

Resultant Forces

Background: Knowledge of transtibial residual limb force and moment loading during gait can be clinically useful. The research question was whether a transducer attached between the socket and pylon can be used to detect differences in loading patterns created by prosthetic feet of different design and different walking activities in real-world environments outside the gait lab. Objectives: To develop methods for obtaining, processing, analyzing and interpreting transducer measurements and examining their clinical usefulness. Study Design: Case series design. Methods: A convenience sample of four K3-K4 transtibial amputees and a wireless tri-axial transducer mounted distal to the socket. Activities included self-selected comfortable speed walking, and ascending and descending ramps and steps. Measurements taken about three orthogonal axes were processed to produce plots of normalized resultant force versus normalized resultant moment. Within-subject differences in peak resultant forces and moments were tested. Results: Loading patterns between feet and subjects and among the activities were distinctly different. Optimal loading of peak resultant forces tentatively might occur around 25% and 69% to73% of stance during self-selected comfortable walking. Ascending and descending ramps is useful for examining heel and forefoot response. Conclusions: Force-moment plots obtained from transducer data may assist clinical decision making. Clinical relevance A pylon-mounted transducer distal to the socket reveals the moments and forces transmitted to the residual limb and can be used to evaluate the loading patterns on the residual limb associated with different foot designs and different everyday activities outside the gait lab.

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Effect of the Cutting Velocity and Heat Treatment on Turning Cutting Forces of an SMA Cu-Al-Be Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.758.157 ◽

2013 ◽

Vol 758 ◽

pp. 157-164

Author(s):

Francisco Valdenor Pereira da Silva ◽

José Paulo Vogel ◽

Rodinei Medeiros Gomes ◽

Tadeu Antonio de Azevedo Melo ◽

Anna Carla Araujo ◽

...

Keyword(s):

Heat Treatment ◽

Shape Memory Alloys ◽

Shape Memory ◽

Cutting Force ◽

Shape Memory Effect ◽

Memory Effect ◽

Chip Formation ◽

Cutting Forces ◽

Cutting Velocity ◽

Resultant Forces

This work studies the effect of heat treatment and cutting velocities on machining cutting forces in turning of a Cu-11.8%Al-0.55%Be shape memory alloys. The heat treatment was performed to obtain samples with austenite and martensite microstructures. Cutting force was investigated using a 3-component dynamometer in several revolutions and data were analyzed using statistic tools. It was found that the resultant forces were higher in quenched alloy due to the presence of Shape Memory Effect. Chip formation occurred in a shorter time in the sample without the Shape Memory Effect.

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The Effects of Posture and Technique on Forces Experienced When Hanging Continuous Miner Cable

Proceedings of the Human Factors and Ergonomics Society Annual Meeting ◽

10.1177/154193129303701028 ◽

1993 ◽

Vol 37 (10) ◽

pp. 779-783 ◽

Cited By ~ 1

Author(s):

Sean Gallagher ◽

Christopher A. Hamrick ◽

Mark S. Redfern

Keyword(s):

Injury Risk ◽

Underground Mines ◽

Ground Reaction Forces ◽

Shear Forces ◽

Lateral Shear ◽

Continuous Miner ◽

Underground Coal Mines ◽

Reaction Forces ◽

Post Hoc ◽

Resultant Forces

Analysis of lost-time back injuries in underground coal mines indicates that handling continuous miner cable places workers at high risk of injury. Manual hanging of this type of cable is a common lifting task in underground mines. This study was performed to assess the ground reaction forces associated with hanging cable in various postures and employing different methods of securing the cable. Seven experienced coal miners (mean age: 41.4 years ± 2.1) performed a series of 12 cable hanging tasks. Independent variables included a set of six posture/vertical space constraint conditions (LIFTCOND), and two techniques of securing the cable to the ceiling (METHOD). The dependent variables consisted of ground reaction forces measured using two force plates. LIFTCOND ( F5.66 = 21.31, p < 0.0001) and METHOD ( F1,66 = 10.89, p < 0.005) both significantly affected the magnitude of the peak resultant forces generated during the tasks. Post hoc analysis indicated that kneeling postures resulted in significantly lower forces than stooping for the same ceiling heights. Greater forces were associated with higher lifting conditions, attributable in part to the fact that higher lifts require more cable to be hoisted. Forces were also increased when subjects twisted baling wire to secure the cable, as compared to hanging it on a hook. An interaction between LIFTCOND and METHOD was identified with lateral shear forces - stooping conditions where the subjects twisted the cable with wire resulted in higher lateral shear forces. Results of this study will be used to develop recommendations to reduce back injury risk when handling cable.

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Quantitative peel test for thin films/layers based on a coupled parametric and statistical study

Scientific Reports ◽

10.1038/s41598-019-55355-9 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 3

Author(s):

Maysam Rezaee ◽

Li-Chih Tsai ◽

Muhammad Istiaque Haider ◽

Armin Yazdi ◽

Ehsan Sanatizadeh ◽

...

Keyword(s):

Thin Films ◽

Statistical Study ◽

Peel Test ◽

Testing Methods ◽

Adhesion Properties ◽

Register Variation ◽

Quantitative Measurements ◽

Test Methodology ◽

Quantitative Results ◽

Resultant Forces

AbstractThe adhesion strength of thin films is critical to the durability of micro and nanofabricated devices. However, current testing methods are imprecise and do not produce quantitative results necessary for design specifications. The most common testing methods involve the manual application and removal of unspecified tape. This overcome many of the challenges of connecting to thin films to test their adhesion properties but different tapes, variation in manual application, and poorly controlled removal of tape can result in wide variation in resultant forces. Furthermore, the most common tests result in a qualitative ranking of film survival, not a measurement with scientific units. This paper presents a study into application and peeling parameters that can cause variation in the peeling force generated by tapes. The results of this study were then used to design a test methodology that would control the key parameters and produced repeatable quantitative measurements. Testing using the resulting method showed significant improvement over more standard methods, producing measured results with reduced variation. The new method was tested on peeling a layer of paint from a PTFE backing and was found to be sensitive enough to register variation in force due to differing peeling mechanisms within a single test.

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Stability estimation of slopes with determined slip surface by the MSTAB-3D method based on sliding body limit equilibrium analysis

MATEC Web of Conferences ◽

10.1051/matecconf/201926204004 ◽

2019 ◽

Vol 262 ◽

pp. 04004

Author(s):

Janusz Ukleja

Keyword(s):

Cross Sections ◽

Slip Surface ◽

Limit Equilibrium ◽

Equilibrium Analysis ◽

Limit Equilibrium Analysis ◽

Modified Method ◽

3D Elements ◽

Resultant Forces ◽

The Impact ◽

Section Analysis

The method developed for this study, established on the premises of the limit equilibrium flat analysis for a spatial solution, is a modification of the STAB-3D method, previously described by the author. It combines the analyses methods of 2D slices of flat cross–sections with the spatial analyses methodology rooted in a specific breakdown of a landslide sliding body into 3D elements assuming some simplifying solution. However, this method is solely applicable in case of a landslide failure with a stipulated slip surface and with a consistent decline of a determined slide direction. Such a method was developed in the article published earlier, which provided then its basic assumptions and the equilibrium formulations. The following publication thereof, presents overall suppositions for this method as well as its modification involving the resultant forces brought to the equilibrium with the generalized slide direction. Apart from that, a comparative analysis was carried out on the impact of this modification applicability of the obtained results with regard to the STAB-3D method. The algorithm was also presented concerning the modified method with its results being compared to a couple of selected methods LEM (limit equilibrium method). The undertaken analysis reveals that the modified MSTAB-3D method determines stability indicators that are very similar to its earlier version. Moreover, the results occur to be also approximating the values obtained in the course of other methods with regard to the flat cross-section analysis.

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Finite Element Analysis and Parametric Study of Spudcan Footing Geometries Penetrating Clay Near Existing Footprints

Journal of Marine Science and Engineering ◽

10.3390/jmse7060175 ◽

2019 ◽

Vol 7 (6) ◽

pp. 175 ◽

Cited By ~ 4

Author(s):

Long Yu ◽

Heyue Zhang ◽

Jing Li ◽

Xian Wang

Keyword(s):

Bending Moment ◽

Vertical Force ◽

Leg Length ◽

Element Analysis ◽

Centrifuge Tests ◽

Flat Base ◽

Key Factor ◽

The Stability ◽

Resultant Forces ◽

Theoretical Analyses

Most existing research on the stability of spudcans during reinstallation nearing footprints is based on centrifuge tests and theoretical analyses. In this study, the reinstallation of the flat base footing, fusimform spudcan footing and skirted footing near existing footprints are simulated using the coupled Eulerian–Lagrangian (CEL) method. The effects of footprints’ geometry, reinstallation eccentricity (0.25D–2.0D) and the roughness between spudcan and soil on the profiles of the vertical force, horizontal force and bending moment are discussed. The results show that the friction condition of the soil–footing interface has a significant effect on H profile but much less effect on M profile. The eccentricity ratio is a key factor to evaluate the H and M. The results show that the geometry shape of the footing also has certain effects on the V, H, and M profiles. The flat base footing gives the lowest peak value in H but largest in M, and the performances of the fusiform spudcan footing and the skirted footing are similar. From the view of the resultant forces, the skirted footing shows a certain potential in resisting the damage during reinstallation near existing footprints by comparing with commonly used fusiform spudcan footings. The bending moments on the leg–hull connection section of different leg length at certain offset distances are discussed.

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Stability Evaluation of Overtopped Concrete Hydraulic Structures Using Computational Fluid Dynamics

Canadian Journal of Civil Engineering ◽

10.1139/cjce-2019-0287 ◽

2020 ◽

Author(s):

Mario Freitas ◽

Etienne Favre ◽

Pierre Léger ◽

Lineu José Pedroso

Keyword(s):

Water Pressure ◽

Back Analysis ◽

Hydrodynamic Pressure ◽

Flow Conditions ◽

Gravity Dams ◽

Pressure Fields ◽

Dam Stability ◽

The Stability ◽

Resultant Forces ◽

Safety Guidelines

A particularly challenging aspect in gravity dam stability assessment is the estimation of the induced hydrodynamic water pressure when water with significant velocity is overtopping gravity dams and flowing in or over spillway components. The water flow conditions, including the related pressure fields and resultant forces, are difficult to quantify accurately. Herein, existing dam safety guidelines to estimate the weight of the overflowing water nappe on gravity dams with rectangular crests are first reviewed. Then, a CFD methodology is developed to improve the simplified estimation of hydrodynamic pressure fields acting on the rectangular crests of submerged gravity dams. The CFD pressures are used as input data to classical structural stability analyses based on the gravity method to more adequately quantify the dam stability during overtopping. A back analysis is also performed on the stability of an existing gated spillway that was overtopped during the 1996 Saguenay flood in Québec.

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Lower Extremity Biomechanics Differ in Prepubescent and Postpubescent Female Athletes during Stride Jump Landings

Journal of Applied Biomechanics ◽

10.1123/jab.19.2.139 ◽

2003 ◽

Vol 19 (2) ◽

pp. 139-152 ◽

Cited By ~ 13

Author(s):

Chris J. Hass ◽

Elizabeth A. Schick ◽

John W. Chow ◽

Mark D. Tillman ◽

Denis Brunt ◽

...

Keyword(s):

Lower Extremity ◽

Repeated Measures ◽

High Speed ◽

Female Athletes ◽

Neuromuscular Control ◽

Common Mechanism ◽

Inverse Dynamic ◽

Recreational Athletes ◽

Increased Risk ◽

Resultant Forces

Epidemiological evidence suggests the incidence of injury in female athletes is greater after the onset of puberty and that landing from a jump is a common mechanism of knee injury. This investigation compared lower extremity joint kinematics and joint resultant forces and moments during three types of stride jump (stride jump followed by a static landing; a ballistic vertical jump; and a ballistic lateral jump) between pre- and postpubescent recreational athletes to provide some insight into the increased incidence of injury. Sixteen recreationally active postpubescent women (ages 18–25 years) and 16 recreationally active prepubescent girls (ages 8–11 years) participated in this study. High speed 3D videography and force plate data were used to record each jumper’s performance of the stride jumps, and an inverse dynamic procedure was used to estimate lower extremity joint resultant forces and moments and power. These dependent variables were submitted to a 2 × 3 (Maturation Level × Landing Sequence) MANOVA with repeated measures on the last factor. The findings indicated that postpubescents landed with the knee more extended (4.4°) and had greater extension moments (approximately 30% greater hip and knee extension moments) and powers (40% greater knee power). Further, the post-pubescent athletes had greater knee anterior/posterior forces as well as medio-lateral resultant forces. The differences found between the two groups suggest there may be anatomical and physiological changes with puberty that lead to differences in strength or neuromuscular control which influence the dynamic restraint system in these recreational athletes. A combination of these factors likely plays a role in the increased risk of injury in postpubescent females.

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Investigation of Vibration Assisted Friction Stir Welding

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.504-506.741 ◽

2012 ◽

Vol 504-506 ◽

pp. 741-746 ◽

Cited By ~ 8

Author(s):

Hamid Montazerolghaem ◽

Mohsen Badrossamay ◽

Alireza Fadaei Tehrani

Keyword(s):

Friction Stir Welding ◽

Axial Force ◽

Process Condition ◽

Welding Process ◽

High Strength ◽

State Spaces ◽

Friction Stir ◽

Fsw Simulation ◽

Resultant Forces ◽

Welding Force

Friction Stir Welding (FSW) is a relatively new solid state joining method that can be used to achieve very good weld quality. This technique is energy efficient, environment friendly, and versatile. The FSW process utilizes a rotating tool in which includes a pin and shoulder to perform the welding process. FSW applications in high strength alloys, such as stainless steel remain limited due to large welding force and consequent tool wear. It has been shown that applying the ultrasonic vibration on some processes such as turning and drilling the resultant forces are decreased and process condition is improved. In this paper the influence of applying vibration on FSW is investigated in simulating tools. For FSW modeling a proper transfer function of axial force has been proposed. The resultant axial force of conventional FSW and Vibration Assisted FSW (VAFSW) are compared in frequency and time domain state spaces. A good correlation between FSW simulation and experiments is observed. For further investigation of VAFSW the response surface of design of experiment (DOE) method is utilized. The influence of changing VAFSW process parameters is investigated. The simulation results indicate that vibration helps to decrease the welding force. Using DOE method the effects of implemented frequency and vibration speed amplitude in FSW are found.

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