Difference Between Polymer Plugged Rubber Bearings (PPRB) and High Damping Rubber Bearings (HDRB)
Great question! While Polymer Plugged Rubber Bearings (PPRB) and High Damping Rubber Bearings (HDRB) both aim to provide high energy dissipation during seismic events, they achieve this in fundamentally different ways. Here's a clear comparison to help distinguish them:
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Difference Between Polymer Plugged Rubber Bearings (PPRB) and High Damping Rubber Bearings (HDRB).
|
Feature |
Polymer Plugged Rubber Bearings (PPRB) |
|
|
Damping Mechanism |
Achieves high damping through the intrinsic properties of the rubber compound itself. |
Achieves damping by inserting high-damping polymer plugs into holes within the rubber bearing. |
|
Internal Structure |
Solid elastomeric layers with embedded steel plates; no holes or plugs. |
Contains engineered holes filled with viscoelastic or thermoplastic polymer plugs that deform under load. |
|
Material Composition |
Specialized rubber compound (e.g., natural or synthetic rubber with additives) that provides both stiffness and damping. |
Standard rubber layers combined with polymer inserts designed specifically to absorb energy. |
|
Design Flexibility |
Entire damping behavior comes from rubber formulation - limited post-manufacturing tunability. |
Damping can be tuned more easily by modifying plug material, geometry, or number of plugs. |
|
Common Use Cases |
Simpler configurations where integrated damping is sufficient and fewer components are desired. |
Projects needing adjustable damping performance or where non-metallic solutions (vs. lead) are preferred. |
|
Environmental Concerns |
Environmentally neutral depending on rubber formulation. |
Usually avoids heavy metals, and polymer plugs can be more environmentally friendly than lead. |
Summary:
HDRBs are monolithic designs with rubber compounds that inherently provide damping.
PPRBs are modular designs where high-damping polymers are added to enhance or tailor performance.
PPRBs offer greater customization and are often favored in newer designs seeking alternatives to lead-filled bearings or where damping needs are more complex.
