Collapse and Deformation of Pads under Heavy Loads
Pads in jacks and lifting equipment are designed to distribute loads safely. Under heavy loading conditions, pads can experience collapse or permanent deformation, compromising safety and performance.
1. Causes of Pad Collapse or Deformation
Overloading: Exceeding the rated load capacity subjects the pad to stress beyond its design limits, leading to crushing or permanent set.
Material Fatigue: Repeated heavy loading cycles cause microstructural damage and reduce the pad’s ability to recover its shape.
Low-Quality Materials: Inferior rubber, polyurethane, or improperly cured materials have reduced compressive strength and elasticity.
Environmental Factors: Exposure to extreme temperatures, UV radiation, or chemicals can weaken the material, making it more prone to deformation.
Aging: Long-term use causes hardening, brittleness, or micro-cracking, reducing load-bearing capacity.
2. Effects of Pad Collapse or Deformation
Reduced Load-Bearing Performance: Deformed pads cannot distribute loads evenly, increasing stress on jack components.
Instability During Lifting: Uneven or collapsed pads may tilt or slip, posing a safety hazard.
Accelerated Wear: Deformation concentrates stress, accelerating wear and potential failure of adjacent components.
Safety Risks: Sudden pad collapse under load can result in jack failure, vehicle damage, or operator injury.
3. Preventive Measures
Adhere to Load Ratings: Always operate within the manufacturer’s specified weight limits.
Use High-Quality Materials: Select pads with high compressive strength, proper curing, and resistance to fatigue.
Environmental Protection: Limit exposure to extreme temperatures, UV light, and chemicals.
Regular Inspection and Replacement: Check pads for signs of deformation, hardening, or cracks, and replace if necessary.
Proper Storage: Store pads in a dry, shaded environment to reduce material degradation.
4. Conclusion
Collapse and deformation of pads under heavy loads result from overloading, material fatigue, low-quality materials, environmental stress, and aging. Proper load management, high-quality pad selection, environmental protection, and regular inspections are essential to maintain performance and ensure operator safety.
References
Gent, A. N. Engineering with Rubber: How to Design Rubber Components. Hanser Publishers, 2012.
Lake, G. J. “Fatigue and Fracture of Elastomers.” Rubber Chemistry and Technology, 2000.
ASTM D412 – Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers—Tension.
ISO 7619-1 – Rubber, Vulcanized or Thermoplastic — Determination of Indentation Hardness.
ASTM D2240 – Standard Test Method for Rubber Property—Durometer Hardness.
