What’s on the Influence Lines poster
A definition and 6 facts worth remembering.
An influence line plots one effect at one fixed point as a unit load travels across the span.
- It describes one point, not the whole member
- The ordinate is the effect of a unit load there
- Put live load over the same-sign area only
- Worst moment often needs a part span loaded
- Point loads: multiply by the ordinate and add
- A UDL: multiply by the area under the line
- Mid-span moment, simple span — Peak L/4
- Reaction at a support — Peak 1.0
- A bridge girder is checked with the axle train parked at the worst ordinate.
Educational reference. Influence lines find the worst load position; the design check that follows is code work.
Questions about the Influence Lines poster
- What’s on the Influence Lines poster?
- A definition and 6 facts worth remembering. An influence line plots one effect at one fixed point as a unit load travels across the span. It describes one point, not the whole member; The ordinate is the effect of a unit load there; Put live load over the same-sign area only; Worst moment often needs a part span loaded; Point loads: multiply by the ordinate and add; A UDL: multiply by the area under the line; Mid-span moment, simple span — Peak L/4; Reaction at a support — Peak 1.0; A bridge girder is checked with the axle train parked at the worst ordinate.. Educational reference. Influence lines find the worst load position; the design check that follows is code work.
- Who is the Influence Lines poster for?
- Influence Lines belongs to the Civil Engineering section rather than to a school year, because engineering is not something one grade owns. Anyone learning structural analysis can pin it up — a beginner, a student mid-course, or someone revising years later.
- When should you use the Influence Lines poster?
- Bridges, crane gantries, anything where the load does not stay put. A wall chart earns its place by being glanceable from where the work is happening, so Influence Lines belongs on the wall where that engineering work actually happens, within glancing distance, rather than filed away.
- What other posters go with Influence Lines?
- Braced vs Moment Frame, Beam Reactions and Bending Stress sit alongside Influence Lines in the Civil Engineering section. Printed together they make a wall rather than a single sheet, which is how a reference set actually gets used.Braced vs Moment FrameBeam ReactionsBending Stress
- Is the Influence Lines poster free to download and print?
- Yes. Influence Lines downloads as a free PDF with no account, no email and no watermark, like everything else in the Civil Engineering section. Print as many copies as you like for a home, a classroom, a library or a tutoring group; reselling the file is the only thing the licence rules out.Read the licence
- What size does the Influence Lines poster print at?
- Influence Lines is a vector PDF laid out for US Letter, and prints on A4 with Fit to page — the same file, no separate download. Because every mark on it is drawn rather than photographed, it stays sharp enlarged to A3, A2 or A1 at a copy shop. Colour carries emphasis only, so a greyscale print of Influence Lines loses nothing.Printing guide
Related posters
Charts that sit alongside Influence Lines on the same wall.
Browse every Civil Engineering poster, or start from the full catalogue.