Abstract: Structural health monitoring systems can be limited to a minimum number of sensors due to cost, complexity, and weight restrictions. Some embodiments described herein pertain to a load and damage identification techniques that utilize one sensor. Several passive force estimation techniques are presented. Some techniques use either the shape or the amplitude of the magnitude of the applied force in the frequency domain. Several techniques iteratively reduce an underdetermined set of equations of motion into many overdetermined systems of equations to solve for the force estimates. The techniques are shown to locate and quantify impulsive impacts with over 97% accuracy and non-impulsive impacts with at least 87% accuracy. Impacts not acting at a specific input degree of freedom are also accurately located depending on the distance away from the modeled input degrees of freedom, and damaging impact forces are quantified by making assumptions about the impulsive nature of the applied force.