A Theory of the Calender Effect in Rubberlike Materials

1945 ◽  
Vol 18 (4) ◽  
pp. 772-779 ◽  
Author(s):  
L. Bilmes
Keyword(s):  
Molecular Structure ◽  
Experimental Data ◽  
Plastic Flow ◽  
Elastic Deformation ◽  
Polyvinyl Chloride ◽  
Mechanical Model ◽  
Temperature Dependent ◽  
Yield Values ◽  
Rubberlike Materials

Abstract The facts relating to the calender effected are briefly stated and illustrated by experimental data obtained with calendered plasticized polyvinyl chloride sheet. The nature of rubberlike deformation is outlined. A theory of the calender effect is proposed in terms of a mechanical model whose relation to molecular structure is indicated. The theory postulates that temperature-dependent yield values be associated with the mechanisms of high elastic deformation and plastic flow.

scholarly journals A Study of Yielding and Plasticity of Rapid Prototyped ABS

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1495
Author(s):  
Dan-Andrei Șerban ◽  
Cosmin Marșavina ◽  
Alexandru Viorel Coșa ◽  
George Belgiu ◽  
Radu Negru
Keyword(s):  
Experimental Data ◽  
Stress State ◽  
Plastic Flow ◽  
Plane Stress ◽  
Yield Criterion ◽  
Numerical Analyses ◽  
Flow Potential ◽  
Stress States ◽  
State Configuration

In this article, the yielding and plastic flow of a rapid-prototyped ABS compound was investigated for various plane stress states. The experimental procedures consisted of multiaxial tests performed on an Arcan device on specimens manufactured through photopolymerization. Numerical analyses were employed in order to determine the yield points for each stress state configuration. The results were used for the calibration of the Hosford yield criterion and flow potential. Numerical analyses performed on identical specimen models and test configurations yielded results that are in accordance with the experimental data.

scholarly journals A mesoscopic model for compression of granular materials

2018 ◽  
Vol 183 ◽  
pp. 01054
Author(s):  
Elisha Rejovitzky
Keyword(s):  
Experimental Data ◽  
Wave Propagation ◽  
Granular Materials ◽  
Mechanical Model ◽  
Sound Speed ◽  
Bulk Material ◽  
High Sensitivity ◽  
Water Fraction ◽  
Protective Structures ◽  
Solid Spheres

The design of protective structures often requires numerical modeling of shock-wave propagation in the surrounding soils. Properties of the soil such as grain-grading and water-fraction may vary spatially around a structure and among different sites. To better understand how these properties affect wave propagation we study how the meso-structure of soils affects their equation of state (EOS). In this work we present a meso-mechanical model for granular materials based on a simple representation of the grains as solid spheres. Grain-grading is prescribed, and a packing algorithm is used to obtain periodic grain morphologies of tightly packed randomly distributed spheres. The model is calibrated by using experimental data of sand compaction and sound-speed measurements from the literature. We study the effects of graingrading and show that the pressures at low strains exhibit high sensitivity to the level of connectivity between grains. At high strains, the EOS of the bulk material of the grains dominates the behavior of the EOS of the granular material.

Research of stamping of unequal channel bars. Part 3. Force parameters and shape change of the billet when extruding channels. 2. Determination of the extrusion force, maximum pressure on the matrix wall and the heights of the walls, taking into account the elastic deformation jf the matrix

2021 ◽  
pp. 63-69
Author(s):  
A.L. Vorontsov
Keyword(s):  
Plastic Flow ◽  
Elastic Deformation ◽  
Shape Change ◽  
Plane Deformation ◽  
Maximum Pressure ◽  
Extrusion Force ◽  
System Of Equations ◽  
The Matrix ◽  
Theory Of Plastic Flow

On the basis of the system of equations of the theory of plastic flow, the forces, the maximum pressure on the wall of the matrix and the heights of the obtained walls when extruding channels are determined, taking into account the elastic deformation of the matrix. Keywords: die forging, extrusion, misalignment, punch, matrix, plane deformation, stresses. [email protected]

DNA CURVATURE OF (CCTG)n · (CAGG)n AND (ATTCT)n · (AGAAT)n REPEATS SEQUENCES

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2921-2926
Author(s):  
Lu CAI
Keyword(s):  
Experimental Data ◽  
Theoretical Prediction ◽  
Mechanical Model ◽  
Polyacrylamide Gel ◽  
Human Diseases ◽  
Dna Curvature ◽  
Statistical Mechanical Model ◽  
Statistical Mechanical

A statistical mechanical model was used to calculate the curvature of the 5 chemically synthesized DNAs which contain repeats sequences ( CCTG )n · ( CAGG )n and ( ATTCT )n · ( AGAAT )n associated with human diseases. 8% polyacrylamide gel analyses were also performed for these 5 DNAs. The results indicate the curvature of the sequences CCTG/bend and ATTCT/bend are larger than that of the sequences CCTG/straight and ATTCT/straight. The curvature of straight/bend is larger than that of CCTG/straight and ATTCT/straight, and smaller than that of CCTG/bend and ATTCT/bend. There exists good consistent between theoretical prediction and experimental data.

Measurement Procedure of Ring Motion with the Use of Highspeed Camera During Electromagnetic Expansion

2012 ◽  
Vol 19 (4) ◽  
pp. 797-804 ◽  
Author(s):  
Jacek Janiszewski
Keyword(s):  
Experimental Data ◽  
Flow Stress ◽  
Plastic Flow ◽  
High Speed ◽  
Optical Measurement ◽  
Measurement Procedure ◽  
Expansion Process ◽  
Calculation Results ◽  
Plastic Flow Stress ◽  
Ring Material

Abstract An optical measurement method of radial displacement of a ring sample during its expansion with velocity of the order 172 m/s and estimation technique of plastic flow stress of a ring material on basis of the obtained experimental data are presented in the work. To measure the ring motion during the expansion process, the Phantom v12 digital high-speed camera was applied, whereas the specialized TEMA Automotive software was used to analyze the obtained movies. Application of the above-mentioned tools and the developed measuring procedure of the ring motion recording allowed to obtain reliable experimental data and calculation results of plastic flow stress of a copper ring with satisfactory accuracy.

scholarly journals Numerical Study on the Temperature-Dependent Viscosity Effect on the Strand Shape in Extrusion-Based Additive Manufacturing

2020 ◽  
Vol 4 (2) ◽  
pp. 46 ◽  
Author(s):  
Behrouz Behdani ◽  
Matthew Senter ◽  
Leah Mason ◽  
Ming Leu ◽  
Joontaek Park
Keyword(s):  
Experimental Data ◽  
Additive Manufacturing ◽  
Polylactic Acid ◽  
Extrusion Process ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Cross Sectional ◽  
Dependent Viscosity

A numerical model that incorporates temperature-dependent non-Newtonian viscosity was developed to simulate the extrusion process in extrusion-based additive manufacturing. Agreement with the experimental data was achieved by simulating a polylactic acid melt flow as a non-isothermal power law fluid using experimentally fitted parameters for polylactic acid. The model was used to investigate the temperature effect on the flow behavior, the cross-sectional area, and the uniformity of the extruded strand. OpenFOAM, an open source simulation tool based on the finite volume method, was used to perform the simulations. A computational module for solving the equations of non-isothermal multiphase flows was also developed to simulate the extrusion process under a small gap condition where the gap between the nozzle and the substrate surface is smaller than the nozzle diameter. Comparison of the strand shapes obtained from our model with isothermal Newtonian simulation, and experimental data confirms that our model improves the agreement with the experimental data. The result shows that the cross-sectional area of the extruded strand is sensitive to the temperature-dependent viscosity, especially in the small gap condition which has recently increased in popularity. Our numerical investigation was able to show nozzle temperature effects on the strand shape and surface topography which previously had been investigated and observed empirically only.

scholarly journals Chemo-Mechanical Model for the Expansion of Concrete Due to Alkali Silica Reaction

2020 ◽  
Vol 10 (11) ◽  
pp. 3807 ◽  
Author(s):  
Lianfang Sun ◽  
Xingji Zhu ◽  
Xiaoying Zhuang ◽  
Goangseup Zi
Keyword(s):  
Experimental Data ◽  
Mechanical Model ◽  
Pore Solution ◽  
Damage Model ◽  
Alkali Silica Reaction ◽  
Swelling Capacity ◽  
Simulation Results

A chemo-damage model is proposed to predict the expansion caused by the alkali silica reaction (ASR). The model covers the formation of the pre-expansion gel driven by alkali and the swelling of the gel driven by water. The swelling capacity of the ASR gel is quantified by the sodium to calcium ratio in the pore solution. The bound alkali in the gel recycled by calcium is also considered in this model. Both external alkali supply and internal alkali released from aggregates are included. Several sets of experimental data are compared with the simulation results for the verification of the model.

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