New method of creating impulsive loads for investigating the dynamic strength of polymer materials

1966 ◽  
Vol 2 (1) ◽  
pp. 93-95
Author(s):  
M. L. Bogorad ◽  
M. A. Loshkarev
Keyword(s):  
Dynamic Strength ◽  
Polymer Materials ◽  
New Method ◽  
Impulsive Loads

The Dynamic Strength of a Representative Double Layer Prismatic Core: A Combined Experimental, Numerical, and Analytical Assessment

2010 ◽  
Vol 77 (6) ◽  
Author(s):  
Enrico Ferri ◽  
V. S. Deshpande ◽  
A. G. Evans
Keyword(s):  
Finite Element ◽  
Double Layer ◽  
Dynamic Compression ◽  
Dynamic Strength ◽  
Element Model ◽  
Free Standing ◽  
The Core ◽  
Impulsive Loads ◽  
Back Face ◽  
Out Of Plane

Dynamic out-of-plane compressive testing was used to characterize the dynamic strength of stainless steel prismatic cores with representative double layer topology to be employed in sandwich panels for blast protection. Laboratory-scaled samples of the representative core unit cell were manufactured (relative density of 5.4%) and tested at constant axial impact velocities (ranging from quasi-static to 140 ms−1). The dynamic strength was evaluated by measuring the stresses transmitted to a direct impact Hopkinson bar. Two-dimensional, plane strain, finite element calculations (with a stationary back face) were used to replicate the experimental results upon incorporating imperfections calibrated using the observed dynamic buckling modes. To infer the response of cores when included in a sandwich plate subject to blast loading, the finite element model was modified to an unsupported (free-standing) back face boundary condition. The transmitted stress is found to be modulated by the momentum acquired by the back face mass and, as the mass becomes larger, the core strength approaches that measured and simulated for stationary conditions. This finding justifies the use of a simple dynamic compression test for calibration of the dynamic strength of the core. An analytical model that accounts for the shock effects in a homogenized core and embodies a simple dual-level dynamic strength is presented and shown to capture the experimental observations and simulated results with acceptable fidelity. This model provides the basis for a constitutive model that can be used to understand the response of sandwich plates subject to impulsive loads.

scholarly journals Development and investigation of device for processing polymer materials by 3D-printing method

2019 ◽  
Vol 5 (3-4) ◽  
pp. 25-32
Author(s):  
Petro Zozulia ◽  
◽  
Oleg Polishchuk ◽  
Nazar Kostyuk ◽  
Andriy Polishchuk ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
3D Printing ◽  
Polymer Materials ◽  
New Method ◽  
3D Printer ◽  
Current State ◽  
Main Components ◽  
Processing Polymer ◽  
Printing Method

The analysis of the current state of 3d industry and prospects for its future. In the work, calculations were made and graphs of dependence were obtained, which influence the work of the auger and the installation itself. A new method of printing parts with polymer granules is described and the principle of operation of the equipment used is described. The picture of the working installation with the main components and the method of its attachment on a 3D printer is presented. The heating modes of the extruder itself are simulated and a thermal diagram of the device is shown, which accurately displays the temperature distribution across the sections.

scholarly journals Visual-Acoustic Sensor-Aided Sorting Efficiency Optimization of Automotive Shredder Polymer Residues Using Circularity Determination

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 284 ◽  
Author(s):  
Jiu Huang ◽  
Chaorong Xu ◽  
Zhuangzhuang Zhu ◽  
Longfei Xing
Keyword(s):  
3D Imaging ◽  
Three Dimensional ◽  
Acrylonitrile Butadiene Styrene ◽  
Polymer Materials ◽  
New Method ◽  
Acoustic Sensor ◽  
3D Image ◽  
Acoustic Frequency ◽  
Sorting Efficiency ◽  
Butadiene Styrene

To reduce the emissions and weight of vehicles, manufacturers are incorporating polymer materials into vehicles, and this has increased the difficulty in recycling End-of-Life vehicles (ELVs). About 25–30% (mass) of an ELV crushed mixture is the unrecyclable material known as automotive shredder residues (ASRs), and most of the vehicle polymers are concentrated in this fraction. Thus, these vehicle polymers are conventionally disposed of in landfills at a high risk to the environment. The only way to solve this problem is through the development of a novel separation and recycling mechanism for ASRs. Our previous research reported a novel sensor-aided single-scrap-oriented sorting method that uses laser-triangulation imaging combined with impact acoustic frequency recognition for sorting crushed ASR plastics, and we proved its feasibility. However, the sorting efficiencies were still limited, since, in previous studies, the method used for scrap size determination was mechanical sieving, resulting in many deviations. In this paper, a new method based on three-dimensional (3D) imaging and circularity analysis is proposed to determine the equivalent particle size with much greater accuracy by avoiding the issues that are presented by the irregularity of crushed scraps. In this research, two kinds of commonly used vehicle plastics, acrylonitrile-butadiene-styrene (ABS) and polypropylene (PP), and their corresponding composite materials, acrylonitrile-butadiene-styrene/polycarbonate (ABS/PC) and polypropylene/ethylene-propylene-diene-monomer (PP/EPDM), were studied. When compared with our previous study, with this new method, the sorting efficiency increased, with PP and PP/EPDM and ABS and ABS/PC achieving about 15% and 20% and 70% and 90%, respectively. The sorting efficiency of ASR polymer scraps can be optimized significantly by using sensor-aided 3D image measurement and circularity analysis.

scholarly journals New Method for Determining the Machine-Hand Welding Times Using Ultrasonic Welding Machines with Rotary Sonotrode

Machines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 330
Author(s):  
Dubravko Rogale ◽  
Snježana Firšt Rogale ◽  
Željko Knezić ◽  
Siniša Fajt
Keyword(s):  
Ultrasonic Welding ◽  
Polymer Materials ◽  
New Method ◽  
Technological Parameters ◽  
New Model ◽  
Technical Parameters ◽  
Technical Textiles ◽  
Mathematical Expressions ◽  
Systematic Development ◽  
Relationship Of

The paper presents a new method for determining the machine-hand welding times of synthetic polymer materials using ultrasonic welding machines with rotary sonotrode. The method is based on the claims and observations of W. Möller intended for the clothing industry in the 1990s, according to which there is a spontaneous drop in sewing speed when strongly curved seams are joined, which is due to the possibility of human reactions. The method for determining machine-hand sewing times of curved seams was well accepted in garment production processes. It is used to standardize production time. Using ultrasonic welding machines with rotary sonotrode, the problem of determining the time of ultrasonic joining of curved seams on clothing or technical textiles remained unsolved. That is why is completely new and original model was created, which combines eight technical parameters of ultrasonic welds, eight technological parameters of the production process and seven ergonomic parameters depending on the psychophysical conditions of the workers. The systematic development of the mathematical relationship of all 23 parameters mentioned and the corresponding mathematical expressions for determining and calculating these parameters are presented. These results were also verified by experimental measurements, which show a favourable correlation between the calculated and measured machine hand times. The relationships between the recommended welding speeds, the critical radii of curvature and the number of reactions required according to Möller and the new model are also presented. An analysis of the success in the application of Möller’s and the new model was also performed.

Electron-diffraction studies in synthetic polymer materials

1983 ◽  
Vol 41 ◽  
pp. 362-365
Author(s):  
D.T. Grubb
Keyword(s):  
Electron Diffraction ◽  
Synthetic Polymer ◽  
Polymer Materials ◽  
Crystallographic Structure ◽  
High Dose ◽  
Electron Dose ◽  
Dose Rates ◽  
First Case ◽  
Diffraction Patterns ◽  
The Many

Diffraction studies in polymeric and other beam sensitive materials may bring to mind the many experiments where diffracted intensity has been used as a measure of the electron dose required to destroy fine structure in the TEM. But this paper is concerned with a range of cases where the diffraction pattern itself contains the important information.In the first case, electron diffraction from paraffins, degraded polyethylene and polyethylene single crystals, all the samples are highly ordered, and their crystallographic structure is well known. The diffraction patterns fade on irradiation and may also change considerably in a-spacing, increasing the unit cell volume on irradiation. The effect is large and continuous far C94H190 paraffin and for PE, while for shorter chains to C 28H58 the change is less, levelling off at high dose, Fig.l. It is also found that the change in a-spacing increases at higher dose rates and at higher irradiation temperatures.

Selective Sampling and Orientation of Non-Homogeneous Tissues

1968 ◽  
Vol 26 ◽  
pp. 98-99
Author(s):  
C. C. Clawson ◽  
L. W. Anderson ◽  
R. A. Good
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Random Sampling ◽  
New Method ◽  
Microscope Examination ◽  
Small Areas ◽  
Selective Sampling ◽  
Large Numbers ◽  
Specific Orientation

Investigations which require electron microscope examination of a few specific areas of non-homogeneous tissues make random sampling of small blocks an inefficient and unrewarding procedure. Therefore, several investigators have devised methods which allow obtaining sample blocks for electron microscopy from region of tissue previously identified by light microscopy of present here techniques which make possible: 1) sampling tissue for electron microscopy from selected areas previously identified by light microscopy of relatively large pieces of tissue; 2) dehydration and embedding large numbers of individually identified blocks while keeping each one separate; 3) a new method of maintaining specific orientation of blocks during embedding; 4) special light microscopic staining or fluorescent procedures and electron microscopy on immediately adjacent small areas of tissue.

Structure-property relationships of PE/PP sandwiched films

1987 ◽  
Vol 45 ◽  
pp. 454-455
Author(s):  
J. Petermann ◽  
G. Broza ◽  
U. Rieck ◽  
A. Jaballah ◽  
A. Kawaguchi
Keyword(s):  
Mechanical Tests ◽  
Polymer Materials ◽  
Ionic Crystals ◽  
Structure Property ◽  
Polymer Systems ◽  
Structure Property Relationships ◽  
Oriented Films ◽  
Materials Used ◽  
Polymer Laminates ◽  
Heated Glass

Oriented overgrowth of polymer materials onto ionic crystals is well known and recently it was demonstrated that this epitaxial crystallisation can also occur in polymer/polymer systems, under certain conditions. The morphologies and the resulting physical properties of such systems will be presented, especially the influence of epitaxial interfaces on the adhesion of polymer laminates and the mechanical properties of epitaxially crystallized sandwiched layers.Materials used were polyethylene, PE, Lupolen 6021 DX (HDPE) and 1810 D (LDPE) from BASF AG; polypropylene, PP, (PPN) provided by Höchst AG and polybutene-1, PB-1, Vestolen BT from Chemische Werke Hüls. Thin oriented films were prepared according to the method of Petermann and Gohil, by winding up two different polymer films from two separately heated glass-plates simultaneously with the help of a motor driven cylinder. One double layer was used for TEM investigations, while about 1000 sandwiched layers were taken for mechanical tests.

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