This simulator puts a wrench on an elastic torsion shaft with a rotary damper. You set how hard you push, how long the lever is and at what angle the force meets the arm, and the scene shows the moment that results and how the shaft twists and settles.
• A 3D wrench, torsion shaft, applied-force arrow and rotary damper that you can orbit, zoom and inspect part by part. • Five sliders: force magnitude (0-100 N), lever length (0.1-0.8 m), force-to-arm angle (0-180 degrees), torsional stiffness (20-150 N m/rad) and rotational damping (1-12 N m s/rad). • Six live readouts: applied moment, perpendicular lever arm, shaft rotation, angular speed, restoring moment and equilibrium rotation. • Two presets: Radial force (no torque despite a nonzero force) and Perpendicular force (an applied moment of 20 N m).
The moment is tau = r F sin(phi), where phi is the angle between the force and the lever arm, so the effective lever arm is r sin(phi). A force pointing straight along the arm (phi = 0 or 180 degrees) gives zero torque however large it is, and a perpendicular force (phi = 90 degrees) gives the full r F. The shaft then behaves as J theta-double-dot + c theta-dot + k theta = tau with J = 2 kg m2, and settles at an equilibrium rotation theta = tau / k in radians.
The shaft is a linear torsional spring with viscous damping and a follower force that keeps a constant angle to the arm. It is not a bolt-tightening or yield model, and no fastener specification is implied. Try the two presets first, then sweep the angle slider with the force fixed and watch the perpendicular lever arm and equilibrium rotation change together.
Both describe the turning effect of a force about a point or axis, r F sin(phi). Mechanical engineers usually say torque for twisting about a shaft axis and moment for bending or rotation effects on structures; the math is the same.
When it passes through the pivot or points along the lever arm. In this lab a force-to-arm angle of 0 or 180 degrees gives a zero perpendicular lever arm, so the shaft does not turn.
The rotary damper resists angular velocity, so it slows the motion and lets the shaft settle without overshoot. The torsion spring, not the damper, supplies the position-dependent restoring moment that sets the final equilibrium angle.
It is a linear torsion model with a constant-angle follower force and viscous damping. It does not include yielding, friction in threads or fastener preload, so it is not a bolt-torque tool.