XdTd¶

Name: XdTd
Author: Nelson Krahenbuhl Salgado

Extended Damage Tolerance Design

Crack Growth Analysis & Damage Tolerance Design

"Designing for Maintenance from Day One"

Free for academic use · BEM-based · Windows & Linux

What is XdTd?¶

XdTd is a specialized engineering tool for aerospace and mechanical engineers who need to analyze crack growth, predict residual strength, and design structures with damage tolerance from day one.

Built on proven Boundary Element Method (BEM) technology, XdTd provides accurate and efficient stress analysis and crack growth predictions for 2D structures reinforced with fastened or bonded stiffeners and/or repair patches. Designed with ease of use in mind, it offers rich graphical outputs that make structural behavior intuitive to understand. Design variables can be quickly modified and alternative configurations compared side by side, including estimated cost and weight.

XdTd is free for academic and non-commercial use — students, researchers, and educators can use the full application at no cost. If you find XdTd valuable and would like to support its continued development, consider making a donation.

See XdTd in Action¶

Residual Strength Analysis

This video demonstrates how to perform a complete Residual Strength Analysis of a stiffened panel typical of aircraft structures using XdTd.

Crack Growth Analysis

This video demonstrates how to determine the number of cycles required for a crack to grow from its minimum detectable size to the critical size using XdTd.

Designing for Maintenance

A design-for-maintenance study: two stiffened-panel alternatives are compared to find the best trade-off between inspection interval, cost, and weight.

Key Features¶

Crack Growth Analysis¶

Crack growth path prediction made efficient with no domain mesh required. Supports multi-site damage analysis where each crack grows at its own rate.

Residual Strength¶

Critical crack length determination with attachment behavior modeled as elastic, plastic, or plastic with deformation limit. XdTd performs nonlinear analysis where each attachment follows its actual stress-strain properties.

Repair Analysis¶

Stress intensity factors and crack growth analysis for cracked panels repaired with single or double patches, either bonded or fastened.

Databases¶

Database-driven design — material properties, attachment properties, and stiffener cross-section properties are all managed through databases, ensuring pre-approved data is used consistently and reducing the risk of input errors. Sample databases are provided, but organizations can create and maintain their own.

Design Comparison¶

Evaluate design alternatives with ease — compare structural performance side by side or overlaid in the same chart, and assess each alternative's cost and weight to find the optimal solution. This capability also makes XdTd an excellent educational tool, allowing students to develop an intuitive understanding of structural behavior and the impact of design variable changes.

Designing for Maintenance from Day One¶

Optimize inspection intervals early — with easy exploration and comparison of design alternatives, XdTd makes it feasible to design for an optimal inspection period from the earliest stages of structural design.

Application Areas¶

Aerospace Structures — Fuselage, wings, pressure bulkheads
Marine Structures — Ship hulls, offshore platforms
Civil Engineering — Bridges, pressure vessels
Any application where damage tolerance assessment or crack growth prediction is required

Quick Links¶

Getting Started

Install XdTd and run your first analysis in minutes

Installation Guide
User Guide

Learn the interface, workflows, and dialogs

User Guide
Reference

Technical details on models, settings, and file formats

Reference
Video Tutorials

Step-by-step video guides for common tasks

Videos

Getting Help¶

About¶

XdTd was created by Nelson Krahenbuhl Salgado, working independently after retirement. His earlier career included aircraft structures work at Embraer S.A. and a PhD in the Boundary Element Method at the Wessex Institute of Technology, UK, under the supervision of Prof. M. H. Aliabadi. XdTd is not affiliated with, nor endorsed by, any of these organisations.

For the research behind XdTd, see the Publications page. For inquiries, see the Contact page.