Polymers tend to lose resistance to deformations (elastic modulus) at high temperatures. A cost effective method to measure the elastic modulus at elevated temperatures is by Dynamical Mechanical Analysis (DMA).
DMA measures the accumulated plastic strain under loading under different mechanical stresses, frequencies and temperatures together. The DMA data processing enables the flexural storage modulus and temperature service range. This method is well supported by ASTM and ISO standards, and widely used in the pipe, automotive and military industries.
Unlike HDPE, which loses engineering value exponentially as temperature rises, Neoloy-based PRS-Neoweb™ shows predictable stiffness vs. temperature for accurate long-term design. Neoloy-based PRS-Neoweb’s effective service range is-40°C to +60°C.
DMA enables an analysis of the effective service temperature range using the following:
- storage modulus (elasticity)
- loss modulus (plasticity)
- loss tangent (an index for major change in mechanical properties, calculated as ratio between loss modulus and storage modulus)
|PERFORMANCE AT ELEVATED TEMPERATURES|
|Flexural Storage Modulus at sample temp:|
|30°C||> 750||MPa||ISO 6721-1|
|45°C||> 650||ASTM E2254|
The DMA analysis is performed in the range plus 150°C to minus 150°C.
DMA Test Method
Polymers tend to lose resistance to deformations (elastic modulus) at high temperatures. However, geocells must be deliver consistent performance under elevated temperatures. A geocell must maintain its shape and not “creep” or expand under dynamic loading, which could cause a loss of confinement or even worse crack and fail.
The flexible (or elastic) storage modulus is a metric of the geocell resistance to elevated temperatures. Dynamical Mechanical Analysis (DMA) is a cost effective method to measure the elastic modulus at elevated temperatures.
Unlike HDPE which is sensitive to high temperatures, Neoloy-based PRS-Neoweb shows predictable stiffness vs. temperature rise for accurate risk analysis and long-term design.