Collapse of Jack Support Blocks Due to Insufficient Load-Bearing Capacity
Jack support blocks are critical components that distribute load and provide stability during lifting operations. Collapse or failure of these blocks due to insufficient load-bearing capacity poses significant safety risks, potentially causing injury, equipment damage, or vehicle damage.
1. Causes of Collapse
Overloading: Exceeding the rated load of the jack or support block can cause permanent deformation or structural failure.
Inadequate Material Selection: Rubber or polymer materials with insufficient hardness, elasticity, or compressive strength cannot sustain the applied load.
Fatigue and Aging: Repeated use over time, especially under high loads, can weaken the block’s structural integrity, reducing its effective load capacity.
Manufacturing Defects: Internal voids, poor compounding, or improper curing during production can reduce the block’s strength.
Improper Design or Thickness: Blocks that are too thin or poorly shaped for the jack configuration may fail under expected loads.
2. Consequences of Collapse
Vehicle Damage: Sudden loss of support can dent, scratch, or deform vehicle chassis or underbody components.
Operator Injury: Rapid block failure increases the risk of crushing or falling hazards.
Jack Damage: Excessive stress transmitted to the jack can cause structural damage or malfunction.
Operational Downtime: Block collapse interrupts maintenance or repair operations, reducing efficiency.
3. Preventive Measures
Adhere to Load Ratings: Always operate within the manufacturer’s specified weight limits.
Proper Material Selection: Use high-strength, wear-resistant, and elastic rubber or polymer compounds suitable for expected loads.
Routine Inspection: Check for signs of fatigue, cracks, or permanent deformation, and replace worn or compromised blocks.
Design Optimization: Ensure adequate thickness, shape, and load distribution features in the block design.
Environmental Protection: Minimize exposure to heat, ozone, UV, and chemicals to maintain material strength and elasticity.
4. Conclusion
Collapse of jack support blocks due to insufficient load-bearing capacity is primarily caused by overloading, material inadequacy, aging, manufacturing defects, or design flaws. Selecting proper materials, adhering to load limits, performing regular inspections, and protecting the blocks from environmental degradation are essential measures to ensure safety, reliability, and extended service life.
References
Gent, A. N. Engineering with Rubber: How to Design Rubber Components. Hanser Publishers, 2012.
ASTM D2000 – Standard Classification System for Rubber Products in Automotive and Industrial Applications.
ISO 7619-1 – Rubber, Vulcanized or Thermoplastic — Determination of Indentation Hardness.
Lake, G. J. “Fatigue and Fracture of Elastomers.” Rubber Chemistry and Technology, 2000.
ISO 2230 – Rubber Products—Guidelines for Storage and Maintenance.
