How is the load-bearing capacity of fiberglass reinforced plastic grating calculated?

I. Core Control Conditions

The load-bearing calculation must simultaneously meet the bending stress limit and deflection limit. In most cases, the deflection is the decisive indicator. For conventional pedestrian platforms, the maximum deflection is allowed not to exceed 1/200 of the span, and for vehicle-passing platforms, it is recommended not to exceed 1/300.

II. Theoretical Calculation Formula

Maximum deflection at the mid-span of concentrated load: Maximum deflection = Load × Span³ ÷ (48 × Elastic Modulus × Section Moment of Inertia)

Maximum deflection of uniformly distributed load: Maximum deflection = 5 × Uniform Load × Span⁴ ÷ (384 × Elastic Modulus × Section Moment of Inertia)

Maximum bending stress: Maximum bending stress = Maximum bending moment × Distance to the farthest fiber of the section ÷ Section Moment of Inertia

Parameter Explanation: Load unit: Newton; Span unit: Millimeter; Ordinary polyester mesh has an elastic modulus of 7000 to 9000 megapascals, vinyl ester mesh has 7500 to 9500 megapascals; The allowable stress for z-direction bending is taken as 80 to 110 megapascals.

III. Engineering Practical Calculation Steps

Step 1: Determine the placement direction of the mesh; The supporting bars must be perpendicular to the supporting beam, and incorrect placement will significantly reduce the bearing capacity;

Step 2: Measure the net span between supports;

Step 3: Differentiate the load type; Single-point pressure is concentrated load, and large-area uniform pressure is uniformly distributed load;

Step 4: Select the mesh thickness, mesh size, and resin type;

Step 5: Preferably retrieve the manufacturer's corresponding load-span parameter table for direct query; When there is no parameter table, conduct theoretical calculation using the formula;

Step 6: Add safety factors; The safety factor for pedestrian platforms is not less than 1.5, and for vehicle and heavy-load chemical platforms, it is not less than 2.0;

Step 7: Compare the calculation results. If both the strength and deflection requirements are met, it is considered qualified.