Is the proposed optimized design less safe than the original one?

In order to ensure that the results obtained through ACE OCP are directly comparable with those implemented in practice, the same FE simulation, material properties, loading conditions and design code requirements are considered for the analysis and design procedures required during the optimization procedure. This is implemented by using the same binary input .SDB (or .EDB) file in the application of ACE OCP. Therefore, the design requirements that were used to assess the original (reference) design of the user, which was labeled a safe one, are also implemented for all designs generated during the optimization procedure. Consequently, the level of safety of the optimized design is, exactly, the same with that of the original one.

How can I verify that the optimized design is safe?

In order to verify that the optimized design is safe (i.e. satisfies all design requirements) the user can use the .SDB (or .EDB) files that correspond to the optimized design and manually perform analysis and design and ensure if there are any error message resulting from the design procedure of SAP2000 (or ETABS).

Is the optimization procedure followed by ACE OCP certified?

ACE OCP is the result of over 20-years of Research and Development including practical experience in structural analysis and design optimization. Furthermore, the methodologies and advanced algorithms integrated into ACE OCP have been validated with the recent publication of the theoretical framework and indicative results in the official Journal of the International Society for Structural and Multidisciplinary Optimization (ISSMO). ACE OCP is based on the next generation computational procedures and the implementation of such computing tools is expected to have a profound impact in optimized design of structural systems, leading to revolutionary changes in civil engineering design practice.

Is it easy to perform optimization procedures with ACE OCP?

The main objective behind the development of ACE OCP is to make structural optimization a simple task for structural engineering practitioners. Default values are generated automatically for the parameters required for the solution of the optimization problem making structural optimization a one-click procedure. These options can further be adjusted by the user using the friendly and intuitive interface of ACE OCP. 

In many cases there is a preference to keep some sections or dimensions of the structural elements unchanged. Is that possible with ACE OCP?

The user has the ability to choose, in advance, any section that must not change during the optimization procedure. Furthermore, the user has the option to choose some dimensions of the sections that should not change. For example, in the case of a beam, its height might be preferable to remain unchanged. ACE OCP provides the option to the user to ‘lock’ the height of this section and keep it unchanged while the corresponding width can change within specific size bounds.

What about the structural elements modeled with area sections, are these optimizable using ACE OCP?

Both frame and area section modeling approaches are supported by ACE OCP and the corresponding structural elements are optimizable. In particular, for area sections (for example, in case of slabs or shear walls), their performance is assessed based on the reinforcement requirements, if a specific threshold (for example 4%) is exceeded then the design is not considered feasible (i.e. that does not satisfy the design requirements).

What about the structural elements that they are assigned with autoselection sections, are these optimizable using ACE OCP?

Structural elements that were assigned to autoselection sections are also optimizable. The section that is assigned to them is selected among the autoselection list that the user created for the specific section type.

I think that SAP2000 and ETABS is, already, performing optimization through autoselection sections. Is this true, what is the difference with ACE OCP?

Indeed, SAP2000 and ETABS perform an optimization-like procedure for the autoselection sections only. The procedure is based on the minimum work concept. However, the resulted design might not be manufacturable; in a sense that it might result to designs where the same structural element is composed by different cross-section along its length, a situation that is neither preferable nor practical. Thus, the grouping per section is lost.

As an engineer I have learned to overdesign and overengineer on purpose. How can ACE OCP help me?

ACE OCP can also be considered as a tool for optimizing the topological arrangement of material into the structural system, eliminating the material volume that is not needed or rearranging material volume to locations of increased strength demands. This feature of ACE OCP can be used for obtaining smart overdesigned and overengineered designs. Thus, targeting to performance objectives (like maximum drift ratio) the overdesigned and overengineered original user design provided can be, further, improved keeping the same overdesign and overengineer level. Furthermore, the user has the capacity to impose preferences related to overdesigned and overengineered of specific structural elements that can be locked (i.e. their dimensions will remain unchanged during the optimization procedure) through the friendly ACE OCP interface.     

What if the user provided design does not satisfy design requirements?

Since safety is the primary objective for ACE OCP, when strength requirements are not satisfied (i.e. strength ratios above one are encountered), then ACE OCP will produce the safest design available within the design bounds provided by the user. It is always suggested, that the original (reference) design does satisfy the design requirements. In that case ACE OCP will result to an optimized design that will also satisfy the design requirements. In case the reference model violates some of the design checks then the resulting design will possibly also not satisfy some of the design checks, however the strength ratio will be improved significantly; since safety is the major concern for ACE OCP.

How many iterations will there be required for convergence/optimum result?

Although, the number of iterations depend on the structural system and the number of sections used for the model, in general around 100 iterations are enough for obtaining an improved design.

Is the application of ACE OCP limited to specific region or country?

ACE OCP is a plugin to ETABS/SAP2000 and takes into account all regional parameters that are integrated into these products, and as such it can be implemented without limitation world-wide. ACE OCP’s friendly user interface allows engineers around the world to specify the material cost in relation to the monetary units that are used in the location under optimization.

Does optimization mean only less costly design?

ACE OCP’s advanced interface allows the option to improve the user provided design based on either performance or cost based criteria. For additional information please contact us at

I believe there are also other software solutions that perform optimization.

ACE OCP is the only software world-wide that performs structural optimization studies over the entire structural system taking into account all design load combinations and code requirements. Other solutions might claim they solve structural optimization problems, however, they only perform a per structural member cross-section suggestion.

What should I enter into the External Plugin Data screen to enable ACE OCP?

First of all make sure you have a model open or create a new empty one – otherwise the menus to add the Plugin will not be enabled.

  • In ETABS 2016 for Plugin Path please use: C:\Program Files\ACE-Hellas\OCP for ETABS2016\ACEOCPE.dll
    This option doesn’t exist in SAP2000 so just skip to add Menu Text and Plugin Name.
  • For Menu Text please use:
    • “ACE OCP”
  • For Plugin Name please use:
    • SAP2000 v18: ACEOCP
    • SAP2000 v19: ACEOCP19
    • ETABS 2016: ACEOCPE
Does ACE OCP support older versions of SAP2000 or ETABS?

ACE OCP uses the Application Programming Interface (API) that SAP2000 and ETABS provides. This is constantly updated and supported at latest versions only. Hence it is not possible to support older version due to lack of API commands. Going forward ACE OCP will be developed and supported on latest versions of SAP2000 and ETABS as new commands, fixes, improvements on the API, developed by CSI are included in latest versions only.

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