pulling force
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2022 ◽  
Vol 9 ◽  
Author(s):  
Zhengdian Xu ◽  
Hong Li ◽  
Yue Jiang ◽  
Qingjiang Xiang ◽  
Pan Tang

To solve the problems of higher energy consumption and lower intelligence of traditional hard hose travelers, a new hard hose traveler with the function of electric drive and self-propelled is developed in this paper. The operational energy consumption of a reel and a polyethylene tube is an important part of hard-hose traveler energy consumption. In this paper, based on the JP50-180 hard hose traveler, the required pulling force and energy consumption at the reel and tube operation are theoretically and experimentally obtained. The aforementioned provides support for reducing energy consumption in the future. The influencing factor that affects the energy consumption of the reel rotation is the tube length, and the influencing factors that affect the energy consumption of the tube sliding are the ground slope, soil moisture content, and tube length. A calculation model for the dynamic change of the pulling force and energy consumption of the reel and tube operation is proposed in this study. Through theoretical analysis, maximum pulling tension and cumulative energy consumption requirements for the for reel rotation are 278.6 N and 15120.83 J, respectively. Furthermore, the requirements for the tube sliding are 1372.86 N and 123,456.96 J. Through test analysis, the maximum pulling tension for the tube sliding is between 1258.3 N and 1773.3 N, while the maximum pulling tension for reel rotation is 285.05 N. Under the same influencing factors, the deviation rates between theoretical and testable energy consumption for the reel rotation and tube sliding are 2.3 and 8.3%, respectively. The pulling force and cumulative energy consumption required for the reel rotation and tube sliding both increase with an increase in their influencing factors. The operating costs of the tube one-time unrolled are approximately 0.0185 CNY. Combined with the mobile resistance of the electric tracked vehicle, the power configuration of this new hard hose traveler is provided by two servo motors with a power of 5500 W each.


2021 ◽  
Vol 8 (3) ◽  
pp. 309-314
Author(s):  
Iis Noventi ◽  
Umdatus Soleha ◽  
Siti Nur Hasina

The main problem in decubitus patients is the risk of damage to skin integrity related to factors: immobility, decreased sensory perception, decreased tissue perfusion, decreased nutritional status, friction and pulling force, advanced age, and increased humidity. The decubitus is a problem faced by patients with chronic diseases, weak conditions, and patients who experience paralysis. This study aimed to analyze the potential of walnut oil in preventing grade 1 decubitus Wounds of bed Rest Patients. This study used a Quasi-Experimental design (pretest-posttest control group). The sample was 20 people, divided into 2 groups; treatment and control. The treatment group received effleurage massage with walnut oil given twice a day for 7 days, while the control group received pressure ulcers prevention treatment according to the SOP applied in the hospital. A total of 10 patients who received massage using walnut oil showed a p-value of 0.04 (<0.05), which meant that walnut oil massage was affected significantly in preventing pressure ulcers. In conclusion, decubitus wounds can be prevented by effleurage massage with walnut oil which is given regularly twice a day.


Author(s):  
Ruth Cayero ◽  
Valentín Rocandio ◽  
Asier Zubillaga ◽  
Ignacio Refoyo ◽  
Julio Calleja-González ◽  
...  

Tug-of-war (TOW) is an internationally played activity including professional and amateur athletes, defined as early as 4000 years ago (as a rope-less version) in the artwork on Egyptian tomb engravings, and is played as per the rules laid out by TWIF, which has 73 member countries and administrative headquarters in the USA. Typically, two teams of “pullers” participate and apply enormous contra directional forces on the pulling rope. Originally, two types of competition are used: knockout and points. This narrative review describes the scientific state of the art of TOW. To the best of the authors’ knowledge, no previous information has been published on this topic. Anthropometric parameters for competitors are near 83.6, lean body mass 69.4, and body fat 16. The VO2MAX is 55.8 mL/kg/min. In terms of relative strength, the dynamic leg power is 4659.8 N. Endurance TOW elicits minimal muscle damage. Injured strains and sprains comprised over half of all injuries: back (42%), shoulder–upper limb (23%) and knee (17%). Pulling movement in TOW contests can be divided into three phases, namely the “drop”, “hold” and “drive” phases. The maximal pulling force was 1041.6 ± 123.9 N. The percentage of dynamic pulling force in the static maximal pulling force was 75.5 ± 14.4% and the dynamic ranged from 106.4 to 182.5%. There are two gripping styles: indoor and outdoor. The friction characteristics between surface and shoe in TOW is important in determining a suitable shoe for indoor TOW. A waist belt might be a useful piece of equipment for TOW sport. The EMG technique in TOW entails a high degree of dorsal muscle activity during the pulling. The factor of force vanishing was the coordination among athletes. The force vanishing percentage goes from 8.82 ± 5.59 for two contenders to 19.74 ± 2.22 for eight athletes, 6.4% in the sum of two pullers. However, in the drop phase, for female elite TOW team, only the 0.5% of the pulling force was wasted. Future studies are need in order to understand better this historical sport activity.


2021 ◽  
pp. 136943322110606
Author(s):  
Zhou Junlong ◽  
Li Dongsheng

This paper presents a semi-theoretical empirical formula to predict the shear-flexural cracking strength of an RC beam enhanced with the external vertical prestressing rebar (EVPR) technique. Besides, nonlinear finite element models (FEM) created by software ABAQUS were used to analyze the effect of crucial parameters on the shear-flexural cracking strength. The parameters involve shear span-to-depth ratio, concrete strength, longitudinal tension reinforcement ratio, initial pulling force and spacing of EVPRs, and the vertical stiffness of the EVPR supports. Results show that the cracking strength increased linearly with the tensile strength of the concrete and the initial pulling force. The small shear span-to-depth ratio was predominantly conducive to the cracking strength. Adequate longitudinal tension rebars contributed to the cracking strength improvement. A reasonable EVPR spacing was recommended to ensure the cracking strength. Greater vertical stiffness of the EVPR supports can ensure higher compressive stress for the RC beam to improve the cracking strength.


Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3376
Author(s):  
Miao Peng ◽  
Hui Luo ◽  
Zhaojian Zhang ◽  
Tengfang Kuang ◽  
Dingbo Chen ◽  
...  

Optical pulling forces, which can pull objects in the source direction, have emerged as an intensively explored field in recent years. Conventionally, optical pulling forces exerted on objects can be achieved by tailoring the properties of an electromagnetic field, the surrounding environment, or the particles themselves. Recently, the idea of applying conventional lenses or prisms as photonic probes has been proposed to realize an optical pulling force. However, their sizes are far beyond the scope of optical manipulation. Here, we design a chiral metalens as the photonic probe to generate a robust optical pulling force. The induced pulling force exerted on the metalens, characterized by a broadband spectrum over 0.6 μm (from 1.517 to 2.117 μm) bandwidth, reached a maximum value of −83.76 pN/W. Moreover, under the illumination of incident light with different circular polarization states, the longitudinal optical force acting on the metalens showed a circular dichroism response. This means that the longitudinal optical force can be flexibly tuned from a pulling force to a pushing force by controlling the polarization of the incident light. This work could pave the way for a new advanced optical manipulation technique, with potential applications ranging from contactless wafer-scale fabrication to cell assembly and even course control for spacecraft.


Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2383
Author(s):  
Zeyuan Liu ◽  
Mei Chen ◽  
Yan Yang ◽  
Chengzi Liu ◽  
Hui Gao

A bearingless switched reluctance motor (BSRM) has the combined characteristics of a switched reluctance motor (SRM) and a magnetic bearing. The hybrid-rotor BSRM (HBSRM) discussed in the paper has a twelve-pole stator and an eight-pole hybrid rotor, which is composed of a cylindrical rotor and a salient-pole rotor. Although the asymmetry of the hybrid rotor makes the structure and magnetic field of the HBSRM more complex, it can always produce a significant amount of magnetic pulling force to levitate a rotor shaft at all the rotor angular positions of each phase, which is not available in a traditional BSRM. The classical mathematical model for a conventional BSRM is valid only when its rotor rotates from the start of the overlap position to the aligned position, and the radial force and torque derived from this model are discontinuous at the aligned positon, which is harmful to the motor’s stable operation. In this paper, a full-period mathematical model on the assumption that the gap permeance is cut apart by straight lines or improved elliptical lines for a 12/8-pole HBSRM is provided. On the basis of this mathematical model, the continuity of the radial force and torque at all the rotor angular positions can be guaranteed, and the fine characteristics of this mathematical model have been verified by simulations.


2021 ◽  
pp. 004051752110608
Author(s):  
Jaewook Ryu ◽  
Sujin Park ◽  
Sumin Helen Koo ◽  
Giuk Lee

This study proposes the Auto-Fit Dial, which is suitable for high-speed fitting; it includes a function that can wind wire at high speed using an energy storage–release mechanism. The Auto-Fit Dial can store energy in advance in the spiral spring via the rotation of the knob cover, and it releases the stored energy to wind the wire when required by pushing the knob cover. Firstly, the concept design and working principle of the Auto-Fit Dial are explained. Next, a detailed design and structural stability analysis of the mechanical components are described based on the design formula and finite-element analysis. An Auto-Fit Dial prototype is manufactured according to the detailed design with the weight, diameter, and height of 9.7 g, 30.5 mm, and 16.7 mm, respectively. The maximum number of rotations is 5.2 turns, which can wind a wire up to a length of 320 mm. The pulling force applied when the Auto-Fit Dial pulls the wire is initially measured as 5.10 N. The time required to wind a 320 mm wire is 0.015 s, which results in an average speed of 21.33 m/s. Moreover, the Auto-Fit Sleeve is fabricated and applied to the arm sleeve to verify the utility of the Auto-Fit Dial, which combines wire and fabric. Finally, the Auto-Fit Vest is developed by applying a protective vest to the Auto-Fit Dial.


2021 ◽  
Vol 2120 (1) ◽  
pp. 012038
Author(s):  
M A M Johnson ◽  
M H Kit ◽  
Y Hoon ◽  
S C Y Koay ◽  
G A Mahdiraji

Abstract This paper presents fiber optic cable design and simulation using SolidWorks software. SolidWorks software is an effective tool that helps design, analyze, and give a better understanding of fiber optic cable capabilities and performances. The model of the fiber optic cable was developed based on the existing fiber optic drop cable. It is composed of mainly four parts: Fiber optic member, fiber-reinforced plastic (FRP) strength member, low smoke zero halogen (LSZH) jacket, and steel wire. A static study was performed to determine the designed model’s ability to endure various levels of pressing and pulling forces. Simulation results showed that the cable can withstand a maximum of 195 N pulling force and 30000 N pressing force with a displacement of 1.78e+02 mm and 4.94e-01 mm respectively. The findings will contribute to the design of a new or novel fiber optic cable that is capable to monitor landslide activities with higher durability in future studies.


2021 ◽  
Vol 6 (12) ◽  
pp. 168
Author(s):  
Auchib Reza ◽  
Ashutosh Sutra Dhar

Small diameter (42 mm) medium density polyethylene (MDPE) pipes are widely used in the gas distribution system in Canada and other countries. They are sometimes exposed to ground movements resulting from landslides or earthquakes. The current design guidelines for evaluating the pipes subjected to ground movement were developed for steel pipes of larger diameters and may not apply to flexible MDPE pipes. This paper evaluates 42 mm diameter MDPE pipes buried in loose sand under axial relative ground movement for developing a design method for the pipes. MDPE is a viscoelastic material; therefore, the behaviour of MDPE pipes exposed to landslides would depend on the rate of ground movements. In this research, full-scale laboratory tests were conducted to investigate the responses of buried pipes under various rates of relative axial displacement. Finite element modelling of the tests was used to interpret the observed behaviour using the continuum mechanics framework. The study revealed that the pulling force on the pipe depends on the rate of relative ground displacement (pulling rate). The nondimensional pulling force possessed a nonlinear relationship with the pulling rate. A rate-dependent interface friction angle could be used to calculate the maximum pulling forces using the conventional design guidelines for the pipes in loose sand. Based on the pulling force, the pipe wall strains can be estimated using the methods available for larger diameter pipes.


Author(s):  
Zeyuan Liu ◽  
Mei Chen ◽  
Zhi Liang

In order to solve the coupling between torque and suspended force of the traditional bearingless switched reluctance motor (BSRM), a bearingless switched reluctance motor with hybrid-rotor (HBSRM) is proposed in this paper. The HBSRM discussed in the paper has a twelve-pole stator and an eight-pole hybrid-rotor composed of a cylindrical rotor and a salient rotor. The magnetic pulling force between cylindrical rotor and stator is used to independently levitate the shaft, and that between salient rotor and stator is used to separately rotate the rotor. So, the HBSRM not only breaks the restriction of the effective output region between torque and suspended force in the traditional BSRM, but also facilitates the decoupling algorithm design and simplifies the levitation control of this bearingless motor. Firstly, the topology, operating mechanism and mathematical model of the proposed HBSRM are introduced respectively. Then the no-load decoupling control and torque ripple of the traditional BSRM and HBSRM are compared. Moreover, the load decoupling control characteristics of HBSRM are presented and verified by simulation analysis.


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