Mechanical Analysis and Simulation of the Thermoforming Process of Thin Polymer Sheets

2012 ◽  
Vol 504-506 ◽  
pp. 1111-1116
Author(s):  
Daniel Ahmad ◽  
Nahiene Hamila ◽  
Khalid Lamnawar ◽  
Philippe Boisse
Keyword(s):  
Mechanical Analysis ◽  
Polymer Materials ◽  
Industrial Processes ◽  
Large Strains ◽  
Integral Forms ◽  
Element Simulation ◽  
Polymer Sheets ◽  
Thin Polymer ◽  
Thermoforming Process ◽  
Infrared Lamps

Most of industrial processes (thermoforming, injection moulding...) require the understanding of thermo-mechanical behaviour of polymeric sheets. Furthermore, the mastery of the deformation of the polymers becomes an important stake. In order to improve and complete the understanding of the deformation of thermoplastic polymer materials during their forming processes, the problem of modelling the thermoforming process for viscoelastic sheet under large strains is considered. The first step of the process that consists in heating the sheet using infrared lamps is taken into account by included a temperature field in viscoelastic behaviour laws under integral forms. The finite element simulation of the different steps will be presented

scholarly journals THE INFLUENCE OF SEVERAL TYPES OF RESINS ON THE DYNAMIC MECHANICAL PROPERTIES OF POLYMER MIXTURE BASED ON BUTYL RUBBER

2020 ◽  
Vol 3 (2) ◽  
pp. 36-45 ◽  
Author(s):  
O. Tarasova ◽  
Yu. Yurkin ◽  
A. Toroschin
Keyword(s):  
Phenol Formaldehyde ◽  
Dynamic Properties ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Strength Properties ◽  
Butyl Rubber ◽  
Polymer Materials ◽  
Polymer Mixture ◽  
Damping Properties ◽  
Dynamic Mechanical

this work is devoted to the problem of developing vibration-damping polymer materials with high damping properties in a wide temperature range. The study of the effect of modifying additives on the strength, damping, adhesive and cohesive properties of a butyl rubber composite is the aim of this work. The task is to identify the actual temperature, frequency, dynamic and mechanical characteristics of a composite material based on butyl rubber depending on the type and concentration of resins. The key methods for studying this problem is the dynamic mechanical analysis method, aimed at obtaining information about changes in the dynamic properties of polymer materials (bond strength with metal when peeling samples of composites, determining the flow resistance of samples, determining the migration of plasticizer). Due to the established experimental dependences, it was found that the addition of resins (3% by weight) in the composition based on butyl rubber leads to an increase in the damping properties of composite materials, and an increase to (4.25% by weight) leads to their decrease. It was established that the obtained filled mixtures with a high damping peak and good adhesive and strength properties are mixtures with the addition of alkyl phenol-formaldehyde resins.

Investigation of a Compound Perforated Panel Absorber With Backing Cavities Partially Filled With Polymer Materials

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
C. Q. Wang ◽  
Y. S. Choy
Keyword(s):  
Sound Absorption ◽  
Normal Incidence ◽  
Polyester Fiber ◽  
Polymer Materials ◽  
Element Simulation ◽  
Parallel Arrangement ◽  
Cavity Configuration ◽  
Absorption Performance ◽  
Good Agreement ◽  
Panel Absorber

The paper concerns the sound absorption performance of a compound absorber which consists of a parallel arrangement of multiple perforated panel absorbers of different backing cavity depths partially filled with poroelastic polymer materials. Three polymer materials are considered: expandable polystyrene (EPS) foam, polymethacrylimide (PMI) foam, and polyester fiber. The normal incidence sound absorption coefficients of the compound panel absorber are tested experimentally. Results show that the former two foams can achieve similar absorption performance to the rigid cavity configuration, while the resonances shift to lower frequencies due to the changes of effective cavity depths. It is also found that the additional attenuation by polymer foams may improve sound absorption, but the effect is marginal. For polyester fiber, results show that it performs more like a single perforated panel absorber. Finite element simulation of the compound panel absorber is also discussed, and good agreement is observed between simulated and experimental results.

Design and Characterization of a Soft Vacuum-Actuated Rotary Actuator

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Liancun Zhang ◽  
Qiang Huang ◽  
Wenkang Wang ◽  
Kangjian Cai
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Simulation Analysis ◽  
Experimental Testing ◽  
Large Change ◽  
Mechanical Analysis ◽  
Ring Structure ◽  
Rotary Actuator ◽  
Element Simulation ◽  
Highly Correlated

Abstract This study provides a type of soft vacuum-actuated rotary actuator. The structures in the actuator are based on different elastomeric structures that comprise a number of interacting elastic radial beams, elastic circumferential beams, and interconnected, deformable sector ring structure air chambers. When negative pressure is applied to the structure, the radial beams bend reversibly into serpentine shapes until adjacent circumferential beams contact each other. This bending results in a large change in the circumferential angle of the structure, but a smaller change in its radial width. Thus, the structure produces rotational motion in its circumferential direction. The design, fabrication, and mechanical analysis of the actuator are introduced, respectively. Moreover, finite element simulation analysis and experimental testing are carried out to study the corresponding relations between the air pressure, rotation angle, and force of the actuator. In addition, the stimulation results and the experimental results of the actuator are statistically analyzed by statistical product and service solutions (spss) statistical software. The test results of the experimental platform are highly correlated with the results of the finite element simulation.

Unzip instabilities: Straight to oscillatory transitions in the cutting of thin polymer sheets

2008 ◽  
Vol 82 (6) ◽  
pp. 64002 ◽  
Author(s):  
P. M. Reis ◽  
A. Kumar ◽  
M. D. Shattuck ◽  
B. Roman
Keyword(s):  
Polymer Sheets ◽  
Thin Polymer

A hydro-bulging mechanism of tailor-welded tubes with dissimilar thickness

2009 ◽  
Vol 224 (1) ◽  
pp. 19-24 ◽  
Author(s):  
G N Chu ◽  
G Liu
Keyword(s):  
Finite Element ◽  
Weld Seam ◽  
Mechanical Analysis ◽  
Length Ratio ◽  
Stress And Strain ◽  
Deformation Characteristics ◽  
Element Analysis ◽  
Element Simulation ◽  
Dissimilar Thickness ◽  
Deformation Compatibility

To reveal the deformation characteristics and influence of dissimilar thickness on hydro-bulging of tailor-welded tubes (TWT), a finite-element analysis (FEA), experiments, and a mechanical analysis were conducted. Based on the stress and strain resulting from finite-element simulation, it was concluded that the deformation of the thicker tube lags behind that of the thinner tube throughout the bulging process. The plastic deformation occurs first at the middle zone of the thinner tube and then extends to the thicker tube crossing the weld seam. In general, the expansion occurring on the two parts with dissimilar thickness is non-uniform. However, the higher the length ratio, the higher the deformation compatibility. When the length ratio reaches 0.8, the deformation between two tubes is almost synchronic. It is concluded that the mechanism for improving the deformation compatibility is to induce a deformation in the thicker tube by enhancing the bulging pressure needed for a deformation in the thinner tube by changing the stress state in the thinner tube and applying the work-hardening effect.

scholarly journals Tough Materials Through Ionic Interactions

2021 ◽  
Vol 9 ◽  
Author(s):  
Linda Salminen ◽  
Erno Karjalainen ◽  
Vladimir Aseyev ◽  
Heikki Tenhu
Keyword(s):  
Thermal Properties ◽  
Ion Pairs ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Polymer Materials ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Shape Stability ◽  
Chemical Crosslinks ◽  
Unique Approach

This article introduces butyl acrylate-based materials that are toughened with dynamic crosslinkers. These dynamic crosslinkers are salts where both the anion and cation polymerize. The ion pairs between the polymerized anions and cations form dynamic crosslinks that break and reform under deformation. Chemical crosslinker was used to bring shape stability. The extent of dynamic and chemical crosslinking was related to the mechanical and thermal properties of the materials. Furthermore, the dependence of the material properties on different dynamic crosslinkers—tributyl-(4-vinylbenzyl)ammonium sulfopropyl acrylate (C4ASA) and trihexyl-(4-vinylbenzyl)ammonium sulfopropyl acrylate (C6ASA)—was studied. The materials’ mechanical and thermal properties were characterized by means of tensile tests, dynamic mechanical analysis, differential scanning calorimetry, and thermogravimetric analysis. The dynamic crosslinks strengthened the materials considerably. Chemical crosslinks decreased the elasticity of the materials but did not significantly affect their strength. Comparison of the two ionic crosslinkers revealed that changing the crosslinker from C4ASA to C6ASA results in more elastic, but slightly weaker materials. In conclusion, dynamic crosslinks provide substantial enhancement of mechanical properties of the materials. This is a unique approach that is utilizable for a wide variety of polymer materials.

scholarly journals Investigation on application of basalt materials as reinforcement for flexural elements of concrete bridges

2015 ◽  
Vol 10 (3) ◽  
pp. 201-206 ◽  
Author(s):  
Viktor Gribniak ◽  
Aleksandr K. Arnautov ◽  
Gintaris Kaklauskas ◽  
Vytautas Tamulenas ◽  
Edgaras Timinskas ◽  
...  
Keyword(s):  
Deformation Behaviour ◽  
High Strength ◽  
Concrete Bridges ◽  
Polymer Materials ◽  
Structural Stiffness ◽  
New Materials ◽  
Basalt Fibre ◽  
Reinforced Polymer ◽  
Polymer Sheets ◽  
Fibre Reinforced Polymer

Basalt polymers are rather new materials for civil engineering; therefore, identification of peculiarities and limitations of application of such polymers in concrete structures (particularly bridges) is of vital importance. This paper experimentally investigates deformation behaviour and cracking of flexural elements, which are predominant parameters governing serviceability of the bridges. Unlike a common practice, the present study is not limited by the analysis of concrete beams reinforced with the polymer bars; it also considers effectiveness of basalt fibre reinforced polymer sheets for repairing the beams. The analysis has revealed that a combination of the high strength and elasticity polymer materials governs the effective repair of the beams by significantly increasing (up to 40%) the structural stiffness.

Finite Element Simulation of Welding of Large Structures

1992 ◽  
Vol 114 (4) ◽  
pp. 441-451 ◽  
Author(s):  
S. Brown ◽  
H. Song
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Three Dimensional ◽  
Mechanical Analysis ◽  
Welding Distortion ◽  
Surrounding Structure ◽  
Element Simulation ◽  
Weld Distortion ◽  
Welding Processes

Current simulations of welding distortion and residual stress have considered only the local weld zone. A large elastic structure surrounding a weld, however, can couple with the welding operation to produce a final weld state much different from that resulting when a smaller structure is welded. The effect of this coupling between structure and weld has the potential of dominating the final weld distortion and residual stress state. This paper employs both two-and three-dimensional finite element models of a circular cylinder and stiffening ring structure to investigate the interaction of a large structure on weld parameters such as weld gap clearance (fitup) and fixturing. The finite element simulation considers the full thermo-mechanical problem, uncoupling the thermal from the mechanical analysis. The thermal analysis uses temperature-dependent material properties, including latent heat and nonlinear heat convection and radiation boundary conditions. The mechanical analysis uses a thermal-elastic-plastic constitutive model and an element “birth” procedure to simulate the deposition of weld material. The effect of variations of weld gap clearance, fixture positions, and fixture types on residual stress states and distortion are examined. The results of these analyses indicate that this coupling effect with the surrounding structure should be included in numerical simulations of welding processes, and that full three-dimensional models are essential in predicting welding distortion. Elastic coupling with the surrounding structure, weld fitup, and fixturing are found to control residual stresses, creating substantial variations in highest principal and hydrostatic stresses in the weld region. The position and type of fixture are shown to be primary determinants of weld distortion.

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