SASIT LAB · STRUCTURAL DESIGN CASE STUDY

Concrete shear wall design:
from material behaviour to reinforcement details.

Topology optimization, nonlinear modelling, material validation, and experimental specimen design.

January 2022–August 2024 · Part-time, remote
Head of the Structural Department | Research & Development

My contribution

At Sasit Lab, I connected structural analysis with the design and detailing of optimized concrete shear walls. My work included numerical modelling, comparisons of optimized and conventional wall behaviour, concrete design checks, reinforcement layouts, foundation and top-beam details, quantities, and documentation for the proposed experimental specimens.

The design process brought together material characterization, structural modelling, and practical requirements for reinforcement, anchorage, moulds, and laboratory setup.

1. Design concept

Concept rendering of a topology-optimized concrete shear wall — Design concept: topology optimization of a concrete shear wall. This rendering illustrates the proposed structural form.

The concept uses topology optimization to develop a concrete wall geometry around its structural load paths, then connects that geometry with reinforcement design and a feasible construction method.

Process diagram connecting a typical concrete component with topology optimization, machine learning, construction and an optimized component — Application concept: a typical concrete component passes through optimization and design before construction of the optimized component; the wider workflow includes machine learning and 3D-printing technology.

Topology optimization, machine learning, and 3D-printing technology form part of the wider project concept. My structural work focused on assessing the components and developing the details needed to take the concept toward physical specimens.

2. HPC testing and numerical material validation

HPC cylindrical specimen after compression testing at Amirkabir University of Technology — HPC compression test: cracking and failure of a cylindrical specimen from the mix designed and tested by our team at Amirkabir University of Technology.

HPC beam specimen in a flexural test frame with marked cracks — HPC flexural test: beam cracking documented during material testing at Amirkabir University of Technology. Experimental responses were compared with numerical material-model results.

Our team designed a high-performance concrete (HPC) mix and tested it at Amirkabir University of Technology. The material-test documentation includes compression testing of cylindrical specimens and flexural testing of beams, with observations of cracking and failure.

The material was then modelled numerically. We compared the simulated responses with the laboratory results to validate the numerical material model before using it in the structural component analyses. This linked the concrete behaviour assumed in the model with measured material performance.

Design purpose: establish a material representation that could support subsequent wall analysis and design decisions.

3. Shear-wall benchmarking before prototype testing

Before the proposed wall-test programme, I carried out a separate numerical validation study using a published reinforced concrete shear-wall specimen. I recreated the wall and its reinforcement in Abaqus, used the Concrete Damage Plasticity model for concrete, and represented reinforcement with wire elements incorporating elastic and plastic properties. The numerical model also included the concrete base.

Mesh sensitivity

I compared coarse, moderate, and fine meshes under the same pushover loading conditions. The report found limited variation in the response, while the fine mesh encountered convergence difficulties after approximately 4 mm of imposed displacement. I selected the moderate mesh for the following analyses.

Pushover benchmark

I compared the Abaqus pushover response with the OpenSeesPy reference model to examine the modelling assumptions and response trends. The first validation report documents this comparison and identifies cyclic validation against the experiment as the next step.

Documented stage: material-test validation and initial wall benchmarking informed the design workflow; the first wall-validation report records cyclic validation as planned follow-up.

OpenSeesPy reference: reinforced concrete shear wall with special boundary elements ↗

4. Optimized and conventional wall behaviour

I developed nonlinear models to examine the lateral behaviour of optimized and ordinary shear walls. The supplied model outputs illustrate the distribution and concentration of response in each geometry and helped inform the design and detailing of critical regions.

Optimized wall, C22016: tensile damage output (DAMAGET).
Conventional wall, CN2002: principal plastic strain output (PE).

These outputs use different response variables and scales. The analysis considered structural response alongside the geometry and reinforcement requirements of the component.

5. Experimental specimen design and detailing

I developed details for the experimental wall assembly, including the foundation, wall reinforcement, top beam, anchorage, and mould geometry. The work translated the numerical design into a coordinated specimen arrangement for laboratory testing.

Critical regions: reinforcement layouts at the wall–foundation and wall–top-beam connections.
General reinforcement: the arrangement of bars and ties across the wall assembly.
Foundation: reinforcement cages, bolt layouts, hole locations, sections, and three-dimensional coordination views.
Top beam: reinforcement and anchorage arrangements shown in the three-dimensional model.
Mould details: opening profiles and dimensional information for the optimized wall geometry.

Experimental shear-wall reinforcement detailing at the critical wall-to-foundation connection — Experimental wall model: reinforcement detailing in the critical region at the foundation connection.

General reinforcement layout of the experimental concrete shear-wall assembly — Experimental wall model: general reinforcement arrangement and normal regions of the assembly.

Experimental wall reinforcement detailing at the critical top-beam connections — Experimental wall model: reinforcement detailing in the critical regions at the top beam.

Deliverables: structural drawings, reinforcement details, bar bending schedules, concrete and steel quantity take-offs, and supporting design checks.

6. Experimental setup and team collaboration

Laboratory loading frames and foundation arrangement for the experimental wall model — Experimental wall setup: laboratory loading frames and specimen foundation arrangement.

Reinforcement assembly and specimen preparation within the laboratory test setup — Experimental wall setup: reinforcement assembly and specimen preparation within the laboratory frame.

Overview of foundation and specimen preparation for the experimental wall setup — Experimental wall setup: overview of the foundation arrangement and specimen preparation.

The project documentation includes laboratory frames, specimen preparation, reinforcement assemblies, and material-test observations. These records place the numerical and detailing work in the context of physical testing and specimen construction.

I worked within the Sasit team and communicated design development through technical reports and coordinated structural documentation.

Team collaboration

Farbod Omidtabrizi and Sasit Lab CEO Sina Novin Vajari in front of Galata Tower in Istanbul — Farbod Omidtabrizi with Sasit Lab CEO Sina Novin Vajari in front of Galata Tower, Istanbul.

What this project demonstrates

My contribution connected material behaviour, numerical checks, component geometry, and reinforcement detailing. The focus was to develop a structural concept into a design that could be assessed, documented, and prepared for testing.

Tools and methods: Abaqus · nonlinear finite element analysis · Concrete Damage Plasticity · ACI 318 design checks · ASCE 7 loading studies · reinforcement detailing · quantity take-offs.

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Concrete shear wall design:from material behaviour to reinforcement details.