Characterization and Constitutive Modeling of a Plasticized Poly(vinyl Chloride) for a Broad Range of Strain Rates

2001 ◽  
Vol 74 (4) ◽  
pp. 560-573 ◽  
Author(s):  
Yan Wang ◽  
Ellen M. Arruda ◽  
Phillip A. Przybylo

Abstract The mechanical behavior, morphological characterization and constitutive modeling of plasticized poly(vinyl chloride) (or PVC) are studied in this paper. The plasticized PVC is tested to large strains over a broad range of strain rates. Uniaxial and plane strain compression data at various constant strain rates ranging from −0.001 to −10 s−1 are collected on a conventional servohydraulic test system. Additional uniaxial impact compression data at approximately constant strain rates ranging from −1160 to −5560 s−1 are obtained using an aluminum split Hopkinson pressure bar apparatus. The large strain load/unload response of the plasticized PVC is nonlinear, it contains hysteresis and plastic deformation, and the initial response is highly rate dependent when the strain rate spans the transition zone between quasi-static and impact strain rates at room temperature. The morphology of plasticized PVC is analyzed via differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA), and described as a physically entangled network. A three-dimensional rate dependent constitutive model for plasticized PVC is developed and shown to successfully predict its stress—strain behavior over a broad range of strain rates.

Author(s):  
Huanran Wang ◽  
Canyuan Cai ◽  
Danian Chen ◽  
Dongfang Ma

Abstract Based on compressive tests, static on 810 material test system (MTS) and dynamic on the first compressive loading in split Hopkinson pressure bar (SHPB) tests at different strain rates and temperatures for Lanthanum (La) cylinder specimens, this study determined Johnson-Cook (J-C) type compressive constitutive equation of La metal. The determined compressive constitutive equation of La metal was calibrated in numerically simulating the recorded large deformations of La cylinder specimens generated by the multi-compressive loadings in SHPB tests. Based on tensile tests, static on MTS and dynamic on the first tensile loading in optimized tensile split Hopkinson bar (TSHB) tests at different strain rates for La sheet specimens, this study determined the J-C type tensile constitutive equation of La metal. It was found that the La sheet specimens were fractured during the first tensile loading in TSHB tests. The numerical simulations of transmitted and reflected pulses of TSHB tests for La sheet specimens using strain rate dependent failure strain criterion were consistent with the experimental data. The relation between dynamic failure strength and strain rates was discussed. From scanning electron microscope investigation of fractured La specimens, it was found that damage evolution patterns at high loading rates tend to become regular.


Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 653
Author(s):  
Amos Muiruri ◽  
Maina Maringa ◽  
Willie du Preez ◽  
Leonard Masu

A study was undertaken on the compressive high strain rate properties and deformation behaviour of Direct Metal Laser-Sintered (DMLS) Ti6Al4V (ELI) parts in two separate forms: as-built (AB) and stress relieved (SR). The high strain rate compression tests were carried out using a Split Hopkinson Pressure Bar test system at ambient temperature. The average plastic strain rates attained by the system were 400 s−1 and 700 s−1. Comparative analyses of the performance (flow stresses and fracture strains) of AB and SR specimens were carried out based on the results obtained at these two plastic strain rates. Microstructural analyses were performed to study the failure mechanisms of the deformed specimens and fracture surfaces. Vickers microhardness test values were obtained before and after high strain rate compression testing. The results obtained in both cases showed the strain rate sensitivity of the stress-relieved samples to be higher in comparison to those of as-built ones, at the same value of true strain.


2008 ◽  
Vol 75 (1) ◽  
Author(s):  
M. Garg ◽  
A. D. Mulliken ◽  
M. C. Boyce

Many polymeric materials undergo substantial plastic strain prior to failure. Much of this post yield deformation is dissipative and, at high strain rates, will result in a substantial temperature rise in the material. In this paper, an infrared (IR) detector system is constructed to measure the rise in temperature of a polymer during high strain rate compression testing. Temperature measurements were made using a high-speed mercury-cadmium-telluride (HgCdTe) single-element photovoltaic detector sensitive in the mid-infrared spectrum (6–12μm), while mechanical deformation was accomplished in a split Hopkinson pressure bar (SHPB). Two representative polymers, an amorphous thermoplastic (polycarbonate (PC)) and a thermoset epoxy (EPON 862/W), were tested in uniaxial compression at strain rates greater than 1000s−1 while simultaneously measuring the specimen temperature as a function of strain. For comparison purposes, analogous measurements were conducted on these materials tested at a strain rate of 0.5s−1 on another test system. The data are further reduced to energy quantities revealing the dissipative versus storage character of the post yield work of deformation. The fraction of post yield work that is dissipative was found to be a strong function of strain for both polymers. Furthermore, a greater percentage of work is found to be dissipative at high rates of strain (>1000s−1) than at the lower rate of strain (0.5s−1) for both polymers; this is consistent with the need to overcome an additional energy barrier to yield at strain rates greater than 100s−1 in these two polymers. The highly cross-linked thermoset polymer was found to store a greater percentage of the post yield work of deformation than the physically entangled thermoplastic.


2019 ◽  
Vol 7 (42) ◽  
pp. 12991-13009 ◽  
Author(s):  
Yi Li ◽  
Mingfei Guo ◽  
Yanbiao Li

Plasticized poly(vinyl chloride) (PVC) gels belong to a class of electroactive polymers (EAPs), which have the ability to realize bending motion, contractile motion, extended motion and crawling motion under electric stimulation.


1984 ◽  
Vol 2 (2) ◽  
pp. 123-141 ◽  
Author(s):  
E.D. Dickens

Experimental Oxygen Index data taken on plasticized poly(vinyl chloride) systems which consisted of just poly(vinyl chloride) resin, PVC, and plasticizer are shown to obey a simple two-parameter equation for plasticizer loadings above 15 weight percent. The empirical equation is further tested using data for similar plasticized PVC compounds based on large number of commercial plasticizers and plasticizer blends. One parameter used in the equation is the Oxygen Index of the pure plasticizer determined using a simple modification of the standard Oxygen Index test procedure. The other parameter is shown to have essentially the same value for all the plasticizers tested. A detailed deriva tion of the empirical model is provided using published flame spread models adapted for the Oxygen Index test. Predictions of the Oxygen Index for the two-component (ideal) plasticized PVC compounds are within 2-3% of the ex perimentally measured values.


2017 ◽  
Vol 27 (10) ◽  
pp. 1589-1600 ◽  
Author(s):  
Chenxu Cao ◽  
Zhiwu Zhu ◽  
Tiantian Fu ◽  
Zhijie Liu

The deformation of frozen soil under impact loading is usually accompanied by the evolution of internal defects and microdamage. By taking the strain and strain rates into account, a rate-dependent damage evolution law is proposed in this study, under the assumption of equivalent strain. Subsequently, a damage-modified rate-dependent constitutive model is proposed to describe the dynamic mechanical properties of frozen soil. A split Hopkinson pressure bar is utilized to test the dynamic mechanical response of frozen soil at different temperatures and high strain rates. The experimental results show that frozen soil produces obvious strain rate and temperature effects, and that there is a linear relationship between the peak stress and temperature. The theoretical results of the proposed constitutive model agree well with the experimental results, verifying the applicability of the model.


RSC Advances ◽  
2017 ◽  
Vol 7 (48) ◽  
pp. 30101-30108 ◽  
Author(s):  
Puyou Jia ◽  
Lihong Hu ◽  
Xiaohui Yang ◽  
Meng Zhang ◽  
Qianqian Shang ◽  
...  

We developed an internal plasticizer of aminated tung oil methyl ester for the production of non-migration, phthalate-free flexible and internally plasticized poly(vinyl chloride) (PVC) materials.


2011 ◽  
Vol 261-263 ◽  
pp. 187-191
Author(s):  
Wan Peng Wang ◽  
Yong Le Hu ◽  
Xin Tao Ren ◽  
Yi Bo Xiong ◽  
Kang Zhao ◽  
...  

In order to systematically study dynamic mechanics character of reactive powder concrete (RPC), impact compression experiments and impact flattened Brazilian disc specimens of RPC have been investigated with modified split Hopkinson pressure bar (SHPB) experimental facility using brass pulse shaper, curves about stress versus strain and other parameters at strain rates of 20.3/s~137.0/s were obtained from impact compression. The dynamic tensile strength and tensile failure strain at strain rates of 3.4/s~26.2/s were obtained from impact flattened Brazilian. For comparison, the quasi-static compress and split tension of RPC were obtained with an MTS 810 materials test system and CSS-88500 electron universal material testing machine.The experimental result show that dynamic compression strength , elastic modulus and failure strain,dynamic tensile strength and failure strain significantly increase comparing to quasi-static experiment, RPC have the character of impact harding and ductility enhancement. RPC exhibit excellent failure patterns at high strain rate. Whether impact compression or impact splitting under strain rate including this paper ’s experiments, the relationship between the DIFC or DIFT and the logarithm of strain rateis linear.


1993 ◽  
Vol 58 (11) ◽  
pp. 2673-2681 ◽  
Author(s):  
Miloslav Kolínský ◽  
Stanislav Ševčík ◽  
Rudolf Lukáš

Low-molecular-weight plasticizers are commonly used in the production of plasticized PVC. However, they readily migrate to the surface of the product, which results in the deterioration of physical properties and contamination of environment. This drawback is eliminated by polymerizing vinyl chloride in water suspension in the presence of a polyester plasticizer and structure stabilizer such as triallyl isocyanurate or the ethylene/vinyl acetate copolymer. The data obtained from water and heptane extractions demonstrate a low extractability of the plasticizer used. Attention is focused on the explanation of the role of structure stabilizers in the polymerization process, and some properties of this new type of plasticized PVC and its possible application areas are discussed.


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