Mechanical Behavior of a Solid Composite Propellant during Motor Ignition

1995 ◽  
Vol 68 (1) ◽  
pp. 146-157 ◽  
Author(s):  
Y. Traissac ◽  
J. Ninous ◽  
R. Neviere ◽  
J. Pouyet
Keyword(s):  
Hydrostatic Pressure ◽  
Simple Shear ◽  
Atmospheric Pressure ◽  
Mechanical Response ◽  
Uniaxial Tensile ◽  
Strain Rates ◽  
Shear Tests ◽  
Composite Propellant ◽  
Pressure Sensitive ◽  
Ultimate Properties

Abstract In order to understand the behavior of composite propellants during motor ignition, a particular study about mechanical and ultimate properties of a Hydroxy-Terminated Polybutadiene (HTPB) filled propellant under superimposed hydrostatic pressure was carried out. The mechanical response of the propellant was obtained for uniaxial tensile and simple shear tests at various temperatures, strain rates and superimposed pressures from atmospheric pressure to 15 MPa. The experimentally observed ultimate properties were found to be strongly pressure sensitive and the data were formalized in a specific stress failure criterion.

A New Instrument for Tensile Testings of Thin Free Standing Films at High Strain Rates

2008 ◽  
Author(s):  
Eran Ben-David ◽  
Doron Shilo ◽  
Daniel Rittel ◽  
David Elata
Keyword(s):  
Mechanical Response ◽  
High Strain ◽  
Measurement Techniques ◽  
Experimental System ◽  
Uniaxial Tensile ◽  
Strain Rates ◽  
High Strain Rates ◽  
Optical Encoder ◽  
Free Standing ◽  
New Instrument

The design of more reliable and sophisticated Micro Electro Mechanical Systems (MEMS) relies on the knowledge, understanding, and ability to control their mechanical response. In recent years, enormous progress has been made in developing new measurement techniques for studying the mechanical response of sub-micro scale specimens. However, there is still a lack of knowledge and testing techniques regarding the response of MEMS structures to mechanical shocks, which can appear during fabrication, deployment, or operation. We present an instrument for testing the mechanical response of thin free standing films under uniaxial tensile stress at high strain rates of up to 2×103 sec-1. The experimental system consists of a micro-device, which contains the freestanding specimen, and an external system, which includes instrumentation for measuring its mechanical response. The components of the external system are controlled by a single interface, and allow for a variety of displacement profiles to be applied to the specimens. All the instrumentation operates at high sampling rates (above 1 MHz) to allow for high strain rate application. The freestanding specimen is produced by MEMS fabrication techniques on a micro-device that also includes S-springs to protect the specimen and aluminum grating lines for measuring the displacement. One side of the chip is pulled by a piezoelectric translation stage, which allows controlling the displacement with a nanometric resolution and applying high velocities and accelerations. The specimen displacement is monitored by an optical encoder device that measure the displacement of the aluminum grating located on the micro-device close to the specimen with an accuracy of about 10 nm. The load is determined by measuring the charge on a piezoelectric PMN-30%PT shear plate, which is connected to the pin that holds the micro-device. The new instrument is applied for studying the response of thin aluminum films with thickness of 0.5–1 μm, width that varies between 5 to 50 μm, and length of 120 μm. The mechanical response of these specimens is measured at different strain rates and is compared to measurement done by nanoindentation.

scholarly journals Constitutive modeling of nonlinear strain and time dependent behaviors of ballistic gelatin at low strain rates

Mechanika ◽  
2020 ◽  
Vol 26 (3) ◽  
pp. 191-196
Author(s):  
Li Liu ◽  
Chuan Ding ◽  
Qianqian Lu
Keyword(s):  
Uniaxial Compression ◽  
Simple Shear ◽  
Constitutive Modeling ◽  
Time Dependent ◽  
Strain Rates ◽  
Compression Tests ◽  
Shear Tests ◽  
Energy Potential ◽  
Nonlinear Strain ◽  
Ballistic Gelatin

The present study is concentrated in constitutive modeling of ballistic gelatin at low strain rates. The relaxation tests, simple shear tests at strain rates ranging from 0.0005/s to 1.245/s and uniaxial compression tests at engineering strain rates ranging from 0.004/s to 0.208/s are carried out, and nonlinear strain and time dependent behaviors of ballistic gelatin are observed. A visco-hyperelastic model is proposed based on the Prony series and the reduced polynomial strain energy potential. The material parameters are obtained by fitting to the data of the relaxation and simple shear tests and validated by predicting the compression stress-strain relationships in the uniaxial compression tests. The nonlinear strain and time dependent behaviors of ballistic gelatin are well captured by the model proposed.

scholarly journals Linking peel and tack performances of pressure sensitive adhesives

Soft Matter ◽  
2020 ◽  
Vol 16 (13) ◽  
pp. 3267-3275 ◽  
Author(s):  
Vivek Pandey ◽  
Antoine Fleury ◽  
Richard Villey ◽  
Costantino Creton ◽  
Matteo Ciccotti
Keyword(s):  
Peel Test ◽  
Strain Rates ◽  
Shear Tests ◽  
Pressure Sensitive Adhesives ◽  
Pressure Sensitive

The performances of Pressure Sensitive Adhesives are generally evaluated combining tack, peel and shear tests. Using an instrumented peel test, we can link the peel and tack performances based on the identification of the pertinent strain rates.

Mechanical Behavior of Rubber at High Strain Rates

2006 ◽  
Vol 79 (3) ◽  
pp. 429-459 ◽  
Author(s):  
C. M. Roland
Keyword(s):  
Hydrostatic Pressure ◽  
Strain Rate ◽  
Mechanical Response ◽  
High Strain ◽  
Glassy State ◽  
Hopkinson Bar ◽  
Strain Rates ◽  
Rate Data ◽  
Split Hopkinson ◽  
Low Strain Rate

Abstract Methods to obtain the mechanical response of rubber at high rates of strain are reviewed. These techniques include the extrapolation of low strain, low strain rate data, the limitations of which are discussed, extrapolations to elevated hydrostatic pressure, and direct determinations using split Hopkinson bar and drop weight testers, as well as miscellaneous methods. Some applications involving rubber at strain rates sufficient to induce a transition to the glassy state are described.

scholarly journals Experimental Study on the Mechanical Behavior of EN08 Steel at Different Temperatures and Strain Rates

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 736 ◽  
Author(s):  
Farid Abed ◽  
Akrum Abdul-Latif ◽  
Ayatollah Yehia
Keyword(s):  
Strain Rate ◽  
Mechanical Response ◽  
Dynamic Compression ◽  
Damage Model ◽  
Tensile Tests ◽  
Dynamic Strain ◽  
Uniaxial Tensile ◽  
Strain Rates ◽  
Compression Tests ◽  
Sem Images

The objective of this paper is to investigate the mechanical response of EN08 steel at quasi-static and dynamic strain rates. Uniaxial tensile tests under quasi-static regime (from 0.0015 s−1 to 0.15 s−1) are conducted on EN08 steel at a range of temperatures between 298 K and 923 K. Dynamic compression tests are also performed by using a drop hammer and by considering different masses and heights to study the material response at strain rates up to 800 s−1. Through the stress-strain responses of EN08 steel, a strong dependency of the yield stress as well as the ultimate strength on the strain rate and temperature is recognized. Furthermore, the strain hardening is highly affected by the increase of temperature at all levels of strain rate. The microstructure of the steel is also examined at a fracture by using SEM images to quantify the density of microdefects and define the damage evolution by using an energy-based damage model.

Tensile Yield Strength of a Material Preprocessed by Simple Shear

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Cai Chen ◽  
Yan Beygelzimer ◽  
Laszlo S. Toth ◽  
Yuri Estrin ◽  
Roman Kulagin
Keyword(s):  
Simple Shear ◽  
Mechanical Response ◽  
Deformation Mode ◽  
Tensile Loading ◽  
Mechanical Tests ◽  
Tensile Yield Strength ◽  
Analytical Relation ◽  
Uniaxial Tensile ◽  
Metallic Materials ◽  
Main Deformation

Modern techniques of severe plastic deformation (SPD) used as a means for grain refinement in metallic materials rely on simple shear as the main deformation mode. Prediction of the mechanical properties of the processed materials under tensile loading is a formidable task as commonly no universal, strain path independent constitutive laws are available. In this paper, we derive an analytical relation that makes it possible to predict the mechanical response to uniaxial tensile loading for a material that has been preprocessed by simple shear and, as a result, has developed a linear strain gradient. A facile recipe for mechanical tests on solid bars required for this prediction to be made is proposed. As a trial, it has been exercised for the case of commercial purity copper rods. The method proposed is recommended for design with metallic materials that underwent preprocessing by simple shear.

scholarly journals Ability of Constitutive Models to Characterize the Temperature Dependence of Rubber Hyperelasticity and to Predict the Stress-Strain Behavior of Filled Rubber under Different Defor Mation States

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 369
Author(s):  
Xintao Fu ◽  
Zepeng Wang ◽  
Lianxiang Ma
Keyword(s):  
Experimental Data ◽  
Temperature Dependence ◽  
Mechanical Response ◽  
Constitutive Models ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Chain Model ◽  
Stress Strain ◽  
Filled Rubber ◽  
Yeoh Model

In this paper, some representative hyperelastic constitutive models of rubber materials were reviewed from the perspectives of molecular chain network statistical mechanics and continuum mechanics. Based on the advantages of existing models, an improved constitutive model was developed, and the stress–strain relationship was derived. Uniaxial tensile tests were performed on two types of filled tire compounds at different temperatures. The physical phenomena related to rubber deformation were analyzed, and the temperature dependence of the mechanical behavior of filled rubber in a larger deformation range (150% strain) was revealed from multiple angles. Based on the experimental data, the ability of several models to describe the stress–strain mechanical response of carbon black filled compound was studied, and the application limitations of some constitutive models were revealed. Combined with the experimental data, the ability of Yeoh model, Ogden model (n = 3), and improved eight-chain model to characterize the temperature dependence was studied, and the laws of temperature dependence of their parameters were revealed. By fitting the uniaxial tensile test data and comparing it with the Yeoh model, the improved eight-chain model was proved to have a better ability to predict the hyperelastic behavior of rubber materials under different deformation states. Finally, the improved eight-chain model was successfully applied to finite element analysis (FEA) and compared with the experimental data. It was found that the improved eight-chain model can accurately describe the stress–strain characteristics of filled rubber.

scholarly journals A nonlinear strain-rate dependent constitutive model for uncured rubber materials under large deformation

2020 ◽  
Vol 37 ◽  
pp. 118-125
Author(s):  
Weihua Zhou ◽  
Changqing Fang ◽  
Huifeng Tan ◽  
Huiyu Sun
Keyword(s):  
Constitutive Model ◽  
Large Deformation ◽  
Mechanical Response ◽  
Uniaxial Tensile ◽  
Hysteresis Phenomenon ◽  
Mechanical Behaviors ◽  
Nonlinear Constitutive Model ◽  
Rate Dependent ◽  
Parallel Networks ◽  
Non Gaussian

Abstract Uncured rubber possesses remarkable hyperelastic and viscoelastic properties while it undergoes large deformation; therefore, it has wide application prospects and attracts great research interests from academia and industry. In this paper, a nonlinear constitutive model with two parallel networks is developed to describe the mechanical response of uncured rubber. The constitutive model is incorporated with the Eying model to describe the hysteresis phenomenon and viscous flow criterion, and the hyperelastic properties under large deformation are captured by a non-Gaussian chain molecular network model. Based on the model, the mechanical behaviors of hyperelasticity, viscoelasticity and hysteresis under different strain rates are investigated. Furthermore, the constitutive model is employed to estimate uniaxial tensile, cyclic loading–unloading and multistep tensile relaxation mechanical behaviors of uncured rubber, and the prediction results show good agreement with the test data. The nonlinear mechanical constitutive model provides an efficient method for predicting the mechanical response of uncured rubber materials.

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