8-Panel Symmetric Pratt Roof Truss

16 m symmetric Pratt roof truss with 7 panel-point loads (40 kN each); teaches Pratt load-path pattern where verticals compress and diagonals tension, and identifies the zero-force apex vertical by bilateral symmetry.

Category: truss · Difficulty: Intermediate

Solution

Support reactions (solver-verified)
SupportRx (N)Ry (N)Mz (N·m)
L001400000
L801400000
Member axial forces (solver-verified)
MemberAxial force (N)Sense
Member L0–L1280000Tension
Member L1–L2240000Tension
Member L2–L3200000Tension
Member L3–L4160000Tension
Member L4–L5160000Tension
Member L5–L6200000Tension
Member L6–L7240000Tension
Member L7–L8280000Tension
Member L0–U1-313050Compression
Member U1–U2-313050Compression
Member U2–U3-268328Compression
Member U3–U4-223607Compression
Member U4–U5-223607Compression
Member U5–U6-268328Compression
Member U6–U7-313050Compression
Member U7–L8-313050Compression
Member L1–U1-40000Compression
Member L2–U2-60000Compression
Member L3–U3-80000Compression
Member L4–U40—
Member L5–U5-80000Compression
Member L6–U6-60000Compression
Member L7–U7-40000Compression
Member L1–U256569Tension
Member L2–U372111Tension
Member L3–U489443Tension
Member L5–U489443Tension
Member L6–U572111Tension
Member L7–U656569Tension

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All reaction values are computed by the StatIQ structural engine, not generated text. Signs follow the solver's convention: a positive Ry acts upward, a negative Ry downward; a positive M is counter-clockwise.