Design for Matching Rail Temperature Force with Fastener Longitudinal Resistance
Q1: Why must thermal force match fastener longitudinal resistance?
A1: Excessive thermal force with insufficient fastener resistance causes rail crawling or buckling; excessive resistance leads to overly high internal stress, risking tensile fracture or joint damage in winter.
Q2: What are the basic requirements for fastener longitudinal resistance in CWR?
A2: Resistance must be sufficiently large and uniform to fully restrain rail expansion and contraction, ensuring no displacement under maximum and minimum temperature conditions.
Q3: What problems occur with insufficient resistance during high summer temperatures?
A3: High rail compression under heat, combined with low resistance, causes lateral rail arching and track buckling, directly endangering traffic safety.
Q4: What risks arise from excessive resistance in low temperatures?
A4: Cold weather puts rails in tension; excessive resistance prevents stress relief, potentially fracturing rails or damaging joint components, especially on older lines.
Q5: How to match resistance and thermal force through on-site adjustment?
A5: Set a reasonable stress-free temperature; retighten clips to design torque; replace high-resistance pads; add anti-crawlers if needed to keep overall resistance within a safe range.