Question

Zero force member in trusses are

select one:

a- in-needed members

b- to prevent out of plane buckling

c- to prevent in-plane buckling

d- to prevent out of plane buckling and on-plane buckling

e- used for architectural purposes

Answer 1

Answer) There are two conditions in a truss structure to define a zero force member are as follows

1) If there is only two members at a joint and no external load is acting at that joint then both the members are zero force members.

2) soppose there are three members at a joint ,two are collinear and there is no external load at that joint then non collinear member will carry zero force and collinear members will carry same load of same nature .

zero force member is used  to provide stiffness to the structure, to reduces the length of the member and sometimes is used for architectural purpose but zero force member will act eventually for all above purpose as in need member.

So best answer based on above given option is that zero force member used as in needed member because both above condition says  no external load at that joint then zero force member ,if load is applied at that joint or current loading changes due to any reason  then those member will also start carrying forces.