"After climbing a great hill, one only finds that there are many more hills to climb.” Nelson Mandela

### Gear Design

Gear Design application is useful designing involute gears from scratch. Users can generate STL data of designed gears and can transfer this data on export files very easily.

Users can save and load layout parameters of designed gears at any time.

Tooth bending strength analysis calculator is included with multiple sharing options, including a pdf file.

Gear Design also includes a CAD interface in front end where users can investigate designed gears visually with their finger gestures (zoom, rotate, twist etc.).

Recent update v1.11:

Now, users can save and restore strength analysis parameters separately.

Working Titles:

-New tab for tooth surface durability analysis

For suggestions, bugs&problems:

### Bolted Joint Analysis

Bolted Joint Analysis for iPad is an educational tool that shows how design changes will affect on clamped system characteristics. Bolted Joint Analysis gives a force diagram and result of its simple calculations for a clamped system under axial external loads. It also gives basic terminology and information to have a better visibility of subject problems.

Bolted Joint Analysis is now available on AppStore! !!

For suggestions, bugs&problems:

### Engine LD

Engine Layout Definitions for iPhone and iPod touch shows how layout changes in an internal combustion engine piston-crank system will affect its engine displacement, its power and dynamic forces.

Any change on engine layout parameters are calculated and reflected on sketches and graphes dynamically which makes this app a comprehensive tool that makes hard concepts be understood.

Engine LD gives graphical plots and lists for displacement volume vs crank angle data and dynamic forces vs crank angle data to support further spreadsheet calculations and basic finite element calculations.

**Recent Update v 1.56:**

**- Minor ****improvements for iPhoneX.**

Recent update v1.51:

Performance improvements

Updates v1.40 and v1.50:

- Calculations are carried either in English or SI units optionally.

- Universal application, new iPad interface enables showing effect of layout changes on power in one screen.

- Stylistic improvements and more options for inlet pressure, temperature and sfc values.

Working titles:

- New table for saving and restoring power calculation parameters.

For suggestions, bugs&problems:

### Mohr’s Circle Stress Analysis

**The Mohr's CSA is an interactive tool. Changing views from stress state to Mohr's Circle presentation by just tapping on screen creates unique way to solve problems very quickly. Calculation results can be also viewed on a formula sheet. This app is an essential for students and practicing engineers.**

**For 2D Mohr's Circle representation, two different optional engineering design sign conventions (SC1 or SC2), which have been referred to in most of the textbooks, can be applied.**

**Capabilities of Mohr’s CSA:**

**-Changes views from stress state to Mohr's Circle presentation by tapping on screen.**

**-2D Mohr's Circle Stress Analysis.**

**-3D Mohr's Circle Stress Analysis.**

**-2D transformations on Mohr's Circle and Stress State View.**

**-Optional sign conventions.**

**-Shows calculations on formula sheet**

**-Multiple sharing options including airport transfer, can open its pdf export file on other available applications (i.e. pdf editors).**

**-Saves and restores input data.**

**-Calculates mathematical functions in entries automatically.**

**-Special keypad for entering formulas.**

**-Responsive entry field: Entry field background color turns to red color in case of unpaired parentheses and turns to green color once parentheses are paired again.**

**Recent Update v 2.24:**

**- A new tab is added for showing calculations on a formula sheet (iPhone).**

**- iPad interface is enriched with a formula view which also shows calculation results.**

**Recent Update v 2.31:**

**- Minor ****improvements for iPhoneX.**

For more suggestions, bugs&problems:

### Goodman FAD

Goodman FAD, Goodman Fatigue Analysis Diagram, is prepared for engineers and students to solve fatigue strength problems easily.

Fatigue, or metal fatigue, is the failure of a component as a result of cyclic stress. When the component is to be designed for infinite life, the endurance limit becomes the criteria of failure. Goodman FAD calculations can be carried with either “residual stress method” or “nominal mean stress method”.

Goodman Diagram constructed automatically once all parameter are entered. Critical points are calculated and given on diagram and judgement belongs to the user based on these points.

Users can save and load basic diagram parameters.

**Recent Update v1.70:**

**- A new tab will be added for showing calculations on a formula sheet (iPhone).**

**- iPad interface will be enriched with a formula view which also shows calculation formulas.**

**Recent Update v 1.71:**

**- Minor ****improvements for iPhoneX.**

**Upcoming Update v2.00:**

- Users will be able to save and restore Sn parameters.

For suggestions, bugs&problems:

support@support@drh.com.trappsforeng.com

### Engineering FMEA

Engineering FMEA for iPad is a new application prepared for quick and easy engineering documentation. Main purpose of the application is educational, enabling structured thinking in engineering problems. It can be also used for different purposes including FMEA reporting, quick delivery of preliminary data for urgent meetings, selecting a team or following corrective actions etc.

A sample FMEA with tutorial content is included at the first installation (clean install is required).

Reporting Capabilities:

Content of full report can be changed by settings buttons.

Each section has also its own specific report buttons.

Users can install and save their project specific logo pictures by tapping on logo picture in notification page.

1) Pre-work report with a editable photo.

2) Team managing table.

3) FMEA table for design or process FMEAs. Severity, occurrence and detection scale descriptions automatically changing with selected type of FMEA entry. Combined design and process FMEA possible in one table.

4) Reviewing documents table.

5) Recommended (corrective) actions report.

Any previously entered record in a table can be retrieved to "entry field" by selecting that row. Once selected, changes can be saved or added as a new record by using command buttons in entry field.

Any previously prepared projects can be duplicated.

Recent update v1.20:

-Free sample project for wind turbines.

For suggestions, ideas, bugs&problems:

### Engineering 8D

Engineering 8D for iPad is prepared for quick and easy engineering documentation. Main purpose of these apps are educational, enabling materials for structured thinking in problem solving. It can be also used for different purposes including incident reporting, quick delivery of preliminary data for urgent meetings, preparing a team list or actions list.

Reporting Capabilities:

Content of full report can be changed by settings buttons.

Each section has also its own specific report buttons.

1) Engineering notice w/ image editing capabilities.

2) Team managing table.

3) 5W2H and Ishikawa Cause-Effect Diagrams.

4) Root cause analysis reporting, 5 why analysis diagram.

5) Containment, corrective and preventive actions in one organised table.

6) Preventing recurrence, review similar systems/process table.

7) Reviewing documents table.

8) Recognition team efforts.

Users can install and save their project specific logos or pictures by tapping on logo picture in notification report.

Any previously entered record in a table can be retrieved to "entry field" by selecting that row. Once selected, changes can be saved or added as a new record by using buttons in entry field.

Any previously prepared projects can be duplicated.

Help content is given in settings tab of each project.

Recent update v1.23:

Performance improvements

Working titles:

- Sample project with tutorial content.

For suggestions, ideas, bugs&problems:

### ODE Solver

In Ordinary Differential Equations (ODE), all derivatives are with respect to single independent variable, often representing time. ODE Solver solves systems of ordinary equations with initial boundary conditions with 4th order Runge Kutta Method. It plots and lists results exporting them via email.

All variables, x, u, and t, should be entered with "$" prefix and ODE Solver does the rest.

Example: Typical Pendulum

dx/dt = $u

du/dt= -pi()**2/4*sin($x)-0.1*$u

Following functions are available in ODE Solver:

Operators:

+ add

- subtract

* multiply

/ divide

** power exponentiation

Functions:

sqrt() - returns the square root of the passed parameter

log() - returns the base 10 log of the passed parameter

ln() - returns the base e log of the passed parameter

exp() - returns e raised to the power of the passed parameter

The trigonometric functions:

dtor() - converts the passed parameter from degrees to radians

rtod() - converts the passed parameter from radians to degrees

sin(), cos(), tan()

Their inverses (asin, acos, atan)

Their reciprocals (csc, sec, cotan)

The reciprocals of the inverses (acsc, asec, acotan)

The hyperbolic variations of all the above functions (sinh, cosh, tanh, asinh, acosh, atanh, csch, sech, cotanh, acsch, asech, acotanh)

Constants:

pi() - returns the value of π.

pi_2() - returns the value of π/2

pi_4() - returns the value of π/4

e() - returns the value of e

**Recent Update v 1.60:**

**- Minor ****improvements for iPhoneX.**

For suggestions, bugs&problems:

### Chatting Calculator

The computational powers of smartphones and tablets have made the humble pocket calculator pretty much obsolete. Chatting Calculator is extremely flexible scientific calculator armed with powerful features.

It displays all of your calculations in chat format, allowing you to quickly reference previous calculations, while editing cursor buttons allow you to go backwards and forwards, with each modification you can compare with previous results. The app includes support for unit conversions on entered formulas.

Chatting Calculator has the graphing mode, which allows users to draw up to two equations on screen. Graphed data can be exported in a cvs file.

Chatting Calculator has a unique keypad design that enables calculate and convert (C&C) at the same time.

**Capabilities:**

- Special keypad suitable for engineering calculations.

- Copying and pasting any previous entry or result by just tapping on its avatar. Pressing any avatar copies its equation entry or calculation result (depending on which is pressed) to input field.

- Cursor arrows enables editing pasted entries.

- Recognizing entries with errors and raising warnings.

- Written equations can be used with unit converter.

- Entry field background color turns to red colour in case of unpaired parentheses and turns to green color once parentheses are paired again.

Recent update v1.61:

Performance improvements

- Now when an avatar is pressed, related entry/result will be appended near cursor position (instead of replacing current entry). Multiple previous results that are calculated separately can be appended on new equations.

**Recent Update v 1.64:**

**- Minor ****improvements for iPhoneX.**

For suggestions, ideas, bugs&problems:

### Dynamics RB

Dynamics of Rigid Bodies application gives opportunity to play with parameters of typical mechanical dynamics problems such as nonlinear pendulum, mass-spring-damper system and projectile motion of a baseball ball. Animations and xy graph plots are given to have better understanding. Optional linear and non-linear problem configurations serve different level of users. Characteristic parameters of equations are given in animations for special testing purposes.

Users can create and email pdf (screenshot) and cvs data.

4th order Runge Kutta solutions are used in reported results. Users are able to alter parameters and precision of the numerical method in every case.

Case 1: Pendulum in fluid friction (air)

Linear case can be set by just setting fluid friction is equal to zero.

Duration and number of steps determine the step size by which you can adjust accuracy.

Case 2: Mass-Spring-Damper system

Damping Ratio and undamped natural frequency are given in animation view for experimenting special cases such as critical damping resonant frequencies etc.

Duration and number of steps determine the step size by which you can adjust accuracy.

Case 3: Projectile motion of a baseball ball in air.

Linear case can be set by just setting drag coefficient (Cd) is equal to zero.

For suggestions, bugs&problems: