Structure Systems and Weldments Comparison Functionality

Article by TriMech Solutions, LLC updated January 2, 2023


How are members defined in SOLIDWORKS weldments or structure systems? Let’s look at the different options that are available for either method. The obvious place to start is with sketches. Both planar and 3D sketches are useful in weldments and structure systems. Once we start using planes or faces, points, and other members to define a member’s length, direction, and orientation we begin to see some of the limitations of weldments. Weldments require sketch lines to define members whereas structure systems have six additional options for defining members, see figure 1. Structure systems offer plenty of alternative options to 3D sketches if those have ever given you difficulty.

primary and secondary member types available in structure systems

Figure 1 – All the primary and secondary member types available in structure systems.

Once you have some members placed you may want to adjust the pierce point of the members relative to the axis you defined. In weldments a group of members share a common pierce point. While structure systems don’t have groups exactly, each primary or secondary member set you make could be viewed as a group. The difference being that in structure systems each member can have their pierce point changed independent of other members. Additionally, structure systems allow for the member profile to be offset horizontally and vertically from its pierce point, see figure 2.

Now that your members are defined, you may need to adjust the various joints in your model. In weldments this is done using a trim order at each joint node. Members can be mitered or butted. If you need to trim, split, or extend a member in weldments you’ll need to use the Trim/Extend feature with bodies and planes. In structure systems, trim and split functions can be performed within the structure system feature itself, along with the corner management feature after exiting structure systems. Members can be trimmed by planes and bodies as you’d expect, but to split members you can input an incremental length to split at or you can set a member to split into multiple equal sized pieces. Additionally, members can also be extended within the structure system feature beyond the previously defined member length. Both methods also feature a way to set gaps between abutting members for either weld gaps or for space for connection elements.

Once you are nearing the end of building your model you may need to add some additional components. In both weldments and structure systems you can add end caps, gussets, weld beads, and fillet beads. An additional feature that structure systems have is the addition of Connection Elements. These are effectively Design Library components specific to structure systems. Typically, they are used for bolted or riveted construction because of their ability to propagate features, like hole patterns, to your structure system members.

pierce point on structure system

Figure 2 – A member in structure systems with its pierce point offset.

As you can see, structure systems have some additional functionality over weldments. The only significant drawback is the rebuild time for larger models with a significant number of members. This performance drawback is significantly offset by patterning, which is a common design practice. To learn more about structure systems, and weldments, check out these videos.

Learn more about Structure Systems and Weldements at:

Related Links

Get Certified SOLIDWORKS Services from Javelin

Javelin Experts can help you to:

Find Related Content by TAG:

TriMech Solutions, LLC

TriMech provides thousands of engineering teams with 3D design and rapid prototyping solutions that work hand-in-hand, from sketch to manufacturing. Javelin became a subsidiary of TriMech Solutions LLC in 2021.