A modified physical model of high-strength water hydraulic artificial muscles considering the effects of geometry and material properties

2021 ◽  
pp. 095440622199907
Author(s):  
Zengmeng Zhang ◽  
Jinkai Che ◽  
Peipei Liu ◽  
Yunrui Jia ◽  
Yongjun Gong
Keyword(s):  
Physical Model ◽  
Relative Error ◽  
Wall Thickness ◽  
Material Properties ◽  
High Strength ◽  
Artificial Muscles ◽  
Operating Pressure ◽  
Rubber Tube ◽  
Contraction Ratio ◽  
Water Hydraulic

Compared with pneumatic artificial muscles (PAMs), water hydraulic artificial muscles (WHAMs) have the advantages of high force/weight ratio, high stiffness, rapid response speed, large operating pressure range, low working noise, etc. Although the physical models of PAMs have been widely studied, the model of WHAMs still need to be researched for the different structure parameters and work conditions between PAMs and WHAMs. Therefore, the geometry and the material properties need to be considered in models, including the wall thickness of rubber tube, the geometry of ends, the elastic force of rubber tube, the elongation of fibers, and the friction among fiber strands. WHAMs with different wall thickness and fiber materials were manufactured, and static characteristic experiments were performed when the actuator is static and fixed on both ends, which reflects the relationship between contraction force and pressure under the different contraction ratio. The deviations between theoretical values and experimental results were analyzed to investigate the effect of each physical factor on the modified physical model accuracy at different operating pressures. The results show the relative error of the modified physical model was 7.1% and the relative error of the ideal model was 17.4%. When contraction ratio is below 10% and operating pressure is 4 MPa, the wall thickness of rubber tube was the strongest factor on the accuracy of modified model. When the WHAM contraction ratio from 3% to 20%, the relative error between the modified physical model and the experimental data was within ±10%. Considering the various physical factors, the accuracy of the modified physical model of WHAM is improved, which lays a foundation of non-linear control of the high-strength, tightly fiber-braided and thick-walled WHAMs.

A Parametric Study on Buckling Response of High Strength Steel Pipes With Anisotropic Material Properties

2012 ◽  
Author(s):  
Ali Fathi ◽  
J. J. Roger Cheng
Keyword(s):  
Yield Strength ◽  
Material Properties ◽  
High Strength Steel ◽  
Transverse Direction ◽  
Kinematic Hardening ◽  
High Strength ◽  
Longitudinal Direction ◽  
Operating Pressure ◽  
Material Anisotropy ◽  
Hardening Material

Highly pressurized pipelines crossing harsh environments need to have two chief materials properties; they should have high strength in transverse direction to resist high operating pressers; and high deformability in the longitudinal direction to accommodate externally induced deformations. Pipeline producers try to deal with this dual demand in their high strength steel (HSS) linepipe products by enhancing the yield strength in the transverse direction and maintaining deformability in the longitudinal direction. This practice results in significant level of anisotropy in yielding and early plastic regions. The effects of material anisotropy on complex pipeline limit states such as local bucking is not fully understood. This paper presents the results of a numerical study on the effects of material anisotropy on the buckling response of HSS pipes. The effects of operating pressure, diameter-to-thickness ratio, material grade, strain hardening and the ratio of longitudinal-to-transversal yield strength were taken into account. Combined (isotropic-kinematic) hardening material modeling technique — previously introduced by the authors — was employed in this study. The results of this study are presented in several graphs showing the variation of the critical buckling strain versus the level of material anisotropy of HSS pipes with different geometry, material and operation conditions. These results provide an insight into the effects of material properties on the buckling resistance of pipes, especially when anisotropy is present.

Modeling and experiments on the drive characteristics of high-strength water hydraulic artificial muscles

2017 ◽  
Vol 26 (5) ◽  
pp. 055023 ◽  
Author(s):  
Zengmeng Zhang ◽  
Jiaoyi Hou ◽  
Dayong Ning ◽  
Xiaofeng Gong ◽  
Yongjun Gong
Keyword(s):  
High Strength ◽  
Artificial Muscles ◽  
Modeling And Experiments ◽  
Water Hydraulic

A Method of Designing and Fabricating Mckibben Muscles Driven by 7 MPa Hydraulics

2012 ◽  
Vol 6 (4) ◽  
pp. 482-487 ◽  
Author(s):  
Kazuhiro Iwata ◽  
◽  
Koichi Suzumori ◽  
Shuichi Wakimoto ◽  
Keyword(s):  
High Power ◽  
Water Pressure ◽  
Fem Analysis ◽  
Artificial Muscle ◽  
High Strength ◽  
Maximum Pressure ◽  
Artificial Muscles ◽  
Rubber Tube ◽  
Robot Hands ◽  
Pbo Fiber

Research has recently been increasing on light weight and high-power robot hands that use artificial muscles. By applying ultra high strength PBO fiber sleeves to McKibben artificial muscles, new hydraulic artificial muscles have been developed in our laboratory. In this research, to apply this technology to a high-power robot easily, we have developed new, thin, hydraulic artificial muscles. While the hydraulic artificial muscles reported in our previous paper were driven by a maximum water pressure of 4 MPa, the newly developed thin muscles are driven by water with a maximum pressure of 7 MPa, resulting in very high force capability. This paper details the materials and structure of the new artificial muscles and reports the results of experiments on them. The muscles developed in this work are based on a sleeve and rubber tube design. The movements of the muscles depend on the angle of the knit of sleeve: an angle of less than 54.5 deg produces contraction while an angle of more than 54.5 deg produces extension. Based on this idea, we optimize, using FEM analysis, the angle of knit of the sleeve of each muscle. As a result, a high powered artificial muscle 21 mm in diameter which generates 8 kN of contraction force has been successfully developed.

Designing CO2 Transmission Pipelines Without Crack Arrestors

2010 ◽  
Author(s):  
Graeme G. King ◽  
Satish Kumar
Keyword(s):  
Wall Thickness ◽  
Carbon Capture ◽  
Power Plants ◽  
Oil And Gas ◽  
Cost Optimization ◽  
Operating Conditions ◽  
Operating Pressure ◽  
Design Work ◽  
Industrial Facilities ◽  
Pipeline Network

Masdar is developing several carbon capture projects from power plants, smelters, steel works, industrial facilities and oil and gas processing plants in Abu Dhabi in a phased series of projects. Captured CO2 will be transported in a new national CO2 pipeline network with a nominal capacity of 20×106 T/y to oil reservoirs where it will be injected for reservoir management and sequestration. Design of the pipeline network considered three primary factors in the selection of wall thickness and toughness, (a) steady and transient operating conditions, (b) prevention of longitudinal ductile fractures and (c) optimization of total project owning and operating costs. The paper explains how the three factors affect wall thickness and toughness. It sets out code requirements that must be satisfied when choosing wall thickness and gives details of how to calculate toughness to prevent propagation of long ductile fracture in CO2 pipelines. It then uses cost optimization to resolve contention between the different requirements and arrive at a safe and economical pipeline design. The design work selected a design pressure of 24.5 MPa, well above the critical point for CO2 and much higher than is normally seen in conventional oil and gas pipelines. Despite its high operating pressure, the proposed network will be one of the safest pipeline systems in the world today.

Development of X90 and X100 Steel Grades for Seamless Linepipe Products

2014 ◽  
Author(s):  
Diana Toma ◽  
Silke Harksen ◽  
Dorothee Niklasch ◽  
Denise Mahn ◽  
Ashraf Koka
Keyword(s):  
Wall Thickness ◽  
Deep Water ◽  
High Strength ◽  
Oil And Gas Industry ◽  
Pipe Material ◽  
Line Pipe ◽  
Materials Development ◽  
Additional Tool ◽  
Technical Requirements ◽  
Steel Grades

The general trend in oil and gas industry gives a clear direction towards the need for high strength grades up to X100. The exploration in extreme regions and under severe conditions, e.g. in ultra deep water regions also considering High Temperature/High Pressure Fields or arctic areas, becomes more and more important with respect to the still growing demand of the world for natural resources. Further, the application of high strength materials enables the possibility of structure weight reduction which benefits to materials and cost reduction and increase of efficiency in the pipe line installation process. To address these topics, the development of such high strength steel grades with optimum combination of high tensile properties, excellent toughness properties and sour service resistivity for seamless quenched and tempered pipes are in the focus of the materials development and improvement of Vallourec. This paper will present the efforts put into the materials development for line pipe applications up to grade X100 for seamless pipes manufactured by Pilger Mill. The steel concept developed by Vallourec over the last years [1,2] was modified and adapted according to the technical requirements of the Pilger rolling process. Pipes with OD≥20″ and wall thickness up to 30 mm were rolled and subsequent quenched and tempered. The supportive application of thermodynamic and kinetic simulation techniques as additional tool for the material development was used. Results of mechanical characterization by tensile and toughness testing, as well as microstructure examination by light-optical microscopy will be shown. Advanced investigation techniques as scanning electron microcopy and electron backscatter diffraction are applied to characterize the pipe material up to the crystallographic level. The presented results will demonstrate not only the effect of a well-balanced alloying concept appointing micro-alloying, but also the high sophisticated and precise thermal treatment of these pipe products. The presented alloying concept enables the production grade X90 to X100 with wall thickness up to 30 mm and is further extending the product portfolio of Vallourec for riser systems for deepwater and ultra-deep water application [1, 3, 4].

Simulation on the Life Expectancy of Fine Blanking Tool Punch for High-Strength Automobile Start Motor Flange

2014 ◽  
Vol 607 ◽  
pp. 612-615
Author(s):  
Jong Deok Kim ◽  
Hyun Jun Ko
Keyword(s):  
Life Expectancy ◽  
Material Properties ◽  
High Strength ◽  
Manufacturing Cost ◽  
Working Process ◽  
Product Cost ◽  
Fine Blanking ◽  
Stamping Process ◽  
Cutting Surface ◽  
Secondary Operations

Fine blanking is a press-working process that permits the production of precise, finished components which are cleanly sheared through the whole cutting surface. The manufacturing cost can be reduced because the secondary operations such as milling and broaching can be eliminated and the multistage combined stamping process can be added. The product cost can increase, however, while the precise fine blanking tool and high cost fine blanking press are required. Therefore it is important to design the fine blanking tool in view of the life expectancy of the punch. In this paper the fatigue simulation of fine blanking tool punch for automobile start motor flange was conducted using the commercial FEA software ANSYS. Initially, the material properties were tested and the fine blanking tool was designed for production experiments. The modelling of tool elements and the fatigue simulation according to repeated loads were conducted. As a result of fatigue simulation, the fine blanking tool punch for start motor flange had been fractured with 3,981 strokes. In the fine blanking production experiments, the fine blanking tool punch had to be regrinded after it was used with 3,425 strokes. It was also found that the fatigue simulation of fine blanking tool punch was conducted with an error of 14%.

scholarly journals Infarcted Left Ventricles Have Stiffer Material Properties and Lower Stiffness Variation: Three-Dimensional Echo-Based Modeling to Quantify In Vivo Ventricle Material Properties

2015 ◽  
Vol 137 (8) ◽  
Author(s):  
Longling Fan ◽  
Jing Yao ◽  
Chun Yang ◽  
Dalin Tang ◽  
Di Xu
Keyword(s):  
Wall Thickness ◽  
Material Properties ◽  
Strain Curve ◽  
Stress And Strain ◽  
Stress Strain ◽  
Material Stiffness ◽  
The Mean ◽  
Lv Volume ◽  
Parameter Values

Methods to quantify ventricle material properties noninvasively using in vivo data are of great important in clinical applications. An ultrasound echo-based computational modeling approach was proposed to quantify left ventricle (LV) material properties, curvature, and stress/strain conditions and find differences between normal LV and LV with infarct. Echo image data were acquired from five patients with myocardial infarction (I-Group) and five healthy volunteers as control (H-Group). Finite element models were constructed to obtain ventricle stress and strain conditions. Material stiffening and softening were used to model ventricle active contraction and relaxation. Systolic and diastolic material parameter values were obtained by adjusting the models to match echo volume data. Young's modulus (YM) value was obtained for each material stress–strain curve for easy comparison. LV wall thickness, circumferential and longitudinal curvatures (C- and L-curvature), material parameter values, and stress/strain values were recorded for analysis. Using the mean value of H-Group as the base value, at end-diastole, I-Group mean YM value for the fiber direction stress–strain curve was 54% stiffer than that of H-Group (136.24 kPa versus 88.68 kPa). At end-systole, the mean YM values from the two groups were similar (175.84 kPa versus 200.2 kPa). More interestingly, H-Group end-systole mean YM was 126% higher that its end-diastole value, while I-Group end-systole mean YM was only 29% higher that its end-diastole value. This indicated that H-Group had much greater systole–diastole material stiffness variations. At beginning-of-ejection (BE), LV ejection fraction (LVEF) showed positive correlation with C-curvature, stress, and strain, and negative correlation with LV volume, respectively. At beginning-of-filling (BF), LVEF showed positive correlation with C-curvature and strain, but negative correlation with stress and LV volume, respectively. Using averaged values of two groups at BE, I-Group stress, strain, and wall thickness were 32%, 29%, and 18% lower (thinner), respectively, compared to those of H-Group. L-curvature from I-Group was 61% higher than that from H-Group. Difference in C-curvature between the two groups was not statistically significant. Our results indicated that our modeling approach has the potential to determine in vivo ventricle material properties, which in turn could lead to methods to infer presence of infarct from LV contractibility and material stiffness variations. Quantitative differences in LV volume, curvatures, stress, strain, and wall thickness between the two groups were provided.

Impact Simulation of a Crashworthy Composite Fuselage Section with Energy-Absorbing Floor

2014 ◽  
Vol 529 ◽  
pp. 102-107
Author(s):  
Hai Bo Luo ◽  
Ying Yan ◽  
Xiang Ji Meng ◽  
Tao Tao Zhang ◽  
Zu Dian Liang
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Dynamic Response ◽  
Relative Error ◽  
High Strength ◽  
Computer Code ◽  
Impact Simulation ◽  
Average Acceleration ◽  
Simulation Results ◽  
Energy Absorbing

A 7.8m/s vertical drop simulate of a full composite fuselage section was conducted with energy-absorbing floor to evaluate the crashworthiness features of the fuselage section and to predict its dynamic response to dummies in future. The 1.52m diameter fuselage section consists of a high strength upper fuselage frame, one stiff structural floor and an energy-absorbing subfloor constructed of Rohacell foam blocks. The experimental data from literature [6] were analyzed and correlated with predictions from an impact simulation developed using the nonlinear explicit transient dynamic computer code MSC.Dytran. The simulated average acceleration did not exceed 13g, by contrast with experimental results, whose relative error is less than 11%. The numerical simulation results agree with experiments well.

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