Forces Acting on Structures - JSS2 Basic technology Past Questions and Answers - page 2
Composite structures combine materials to optimise performance under:
Static loads only
Bending and torsion
Compression and tension
Shear and bending
What type of force is a combination of compression and tension, causing a structure to bend or flex?
Shear
Torsion
Bending
Compression
Which force type involves equal and opposite torques applied to twist an object around an axis?
Compression
Tension
Shear
Torsion
What advantage do frame structures have in managing various forces?
They distribute loads through curved surfaces
They evenly distribute tension forces
They allow for flexible design
They resist shear forces with internal supports
Which type of structure is vulnerable to shear forces and requires careful design for lateral stability?
Frame structures
Shell structures
Composite structures
All of the above
What is compression, and how does it affect materials in structures?
Compression is a force that tends to squeeze or shorten a material by pushing its particles closer together. In structures, compression is countered by materials that can withstand this squeezing force, such as columns and vertical members in frame structures. It plays a critical role in supporting the weight of buildings and bridges, ensuring stability and preventing structural failure due to buckling or crushing.
Explain tension and its significance in structural design.
Tension is a force that stretches or elongates a material by pulling its particles apart. In structural design, tension forces are managed through elements like cables and ropes, which are designed to resist pulling forces. Tension is crucial in applications such as suspension bridges and cables supporting roof structures, where the ability to withstand stretching forces is essential for maintaining structural integrity and safety.
What role does shear play in the stability of structures?
Shear is a force that causes parts of a material to slide past each other in opposite directions. In structures, shear forces can lead to deformation or failure if not properly accounted for. They are particularly significant in beams subjected to lateral loads like wind or earthquakes. Designing structures to resist shear involves ensuring adequate connections and bracing to prevent excessive movement or displacement under applied forces.
How do bending forces affect beams and other structural elements?
Bending forces result from a combination of compression on one side and tension on the opposite side of a structural element, such as a beam. These forces cause the material to bend or flex under load. Bending is critical in structural design because it determines the capacity of beams and similar elements to support loads without excessive deformation or failure. Properly designed beams distribute bending stresses to optimise structural performance and ensure durability under varying loads.
Describe torsion and its application in structural engineering.
Torsion is a twisting force that causes an object to rotate around its axis. In structural engineering, torsional forces are significant in components like shafts and helicopter blades, where rotational motion is involved. Designing structures to withstand torsion involves selecting materials and shapes that can resist twisting without excessive deformation or failure. Torsional strength is crucial in ensuring the reliability and efficiency of rotating machinery and structural components subjected to rotational forces.