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Master Project · SIM-01-FEA

Advanced Simulation & FEA

ANSYS · MATLAB · InterShear · In-Plane Decoupling

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Digital Shearography Interference Pattern

01 / THEORY

The Challenge

Shearography is mainly for out-of-plane measurement. The core goal is to achieve in-plane detection.

Adaptation

02 / SIMULATION

Design & FEA

Specimen designed and analyzed in ANSYS to generate controlled in-plane structural deformation.

360 N Loading

03 / OPTICAL

Dual-Beam Setup

Optical setup modified with 45° illumination and phase subtraction to isolate in-plane movement.

InterShear Pipeline

04 / RESULT

Differentiation

Successfully detected and differentiated in-plane deformation caused by weld geometric changes.

2-Edge vs 3-Edge

Overcoming OOP
Limitations

Structural Rigidity
& Deformation

Phase Subtraction
Decoupling

In-Plane Deformation
Achieved

Explore the methodology

Project Context

The Challenge

Adapting Out-of-Plane Tech for In-Plane

Digital Shearography is traditionally designed to measure out-of-plane deformation. The challenge was to develop a simulation framework that adapts this original setup to accurately capture and evaluate early-stage in-plane deformation.

The Solution

Simulation-Driven Geometric Evaluation

Using a combined pipeline of ANSYS, InterShear, and MATLAB, we can simulate fringe interference. By differentiating between two models with distinct geometric changes, we can evaluate structural performance and drive data-backed redesign decisions.

Mathematical Core

The Key Equation: Optical Decoupling

By illuminating from two symmetric angles (+θ and −θ at 45°), two phase distributions are generated. Their subtraction eliminates the out-of-plane term and doubles in-plane sensitivity. Click any annotation to learn more.

N_+θ = (δ_x / λ) · [ (∂u/∂x) sin(θ) + (∂w/∂x)(1 + cos(θ)) ]

N_−θ = (δ_x / λ) · [ −(∂u/∂x) sin(θ) + (∂w/∂x)(1 + cos(θ)) ]

N_diff = N_+θ − N_−θ = [ 2δ_x sin(45°) / λ ] · (∂u/∂x)

Out-of-Plane Coupling

ELIMINATED

In-Plane Sensitivity

×2 DOUBLED

Illumination Angle

θ = 45°

N_+θ

Positive-angle phase map

Fringe order from the +45° illumination beam. Contains both in-plane (∂u/∂x) and out-of-plane (∂w/∂x) contributions.

→ See FEA Setup

δ_x / λ

Shear-to-wavelength ratio

Governs fringe sensitivity. Larger shear distance δ_x or shorter wavelength λ both increase fringe count per unit strain.

→ See Optical Params

N_diff

Differential phase map (result)

The key output: pure in-plane strain derivative ∂u/∂x, decoupled from bending noise. This is the innovation.

→ See Results

Parametric Investigation

Research Hierarchy

LEVEL 01

Step 1 — The Setup

Adapting Digital Shearography for in-plane deformation

Unlocked

The first step is establishing the baseline design. We take the original optical setup of digital shearography, which is inherently built for out-of-plane measurement, and adapt the simulation framework to isolate in-plane deformation.

Foundation: Preparing the base virtual environment to accurately capture strain fields before introducing geometric variables.