Principles and Practice of Engineering (PE) Civil: Structural Practice Exam 2025 - Free PE Civil Structural Practice Questions and Study Guide

When an extra member is added within a truss, it is classified as internal redundancy. Internal redundancy refers to the presence of additional members within a structure that provide alternative load paths. This redundancy can enhance the stability and load-carrying capacity of the truss by allowing it to redistribute forces in the event of failure or excessive loading.

Adding an internal member can lead to an increase in the overall safety of the structure, as it provides an added degree of freedom for load distribution. In contrast, external redundancy would relate to elements that are part of the structure but lie outside the primary load-bearing framework, such as external bracing. Static redundancy involves scenarios in which multiple load paths can be utilized, but the question pertains directly to the additional member's location within the truss structure, confirming it as internal redundancy. Dynamic redundancy would refer to considerations related to structures under dynamic loading conditions, such as those affected by wind or seismic forces, and is not the focus of this scenario.