calcbond User Manual


User Manual

Introduction

calcbond is an online platform for the calculation and presentation of bonded joints and adhesive materials. It offers users the possibility to compile and perform a calculation using predefined calculation systems consisting of a joint geometry, load scenarios, mechanical boundary conditions, and material parameters provided by adhesive manufacturers. Generally known and common analytical methods from the technical literature as well as numerical calculation methods are used.

This User Manual is version 1.0. We apologize for any gaps in the early phase of the platform. We are constantly working to improve this document.

General notes on the use of the main page

After successfully logging into the platform, the user is on the main page of the platform. On this page it is possible to navigate back from any area of the platform by clicking the calcbond logo on the upper left corner of the screen.

The middle section of the home page contains the latest information, renewals of the platform and general information.

At the bottom of the platform are the imprint, the terms of use, and the service descriptions. In the upper right corner is the user's personal information area.

On the left edge of the screen is the platform navigation bar. The bar is divided into three sections:

  1. Work area: Adhesive Joint Design
  2. Technical informative area and
  3. Formal area

The workspace: Adhesive Joint Design

The work area contains the platform's work center. In addition, this area houses material cards and saved calculations.

The Adhesive Joint Design workspace consists of the following sections:

  1. Adhesive Joint App
  2. AutoFEA
  3. Material Cards
  4. My Calculations

The second professional-informative section includes the following headings:

  1. FAQ
  2. Wiki
  3. User Manual

The third formal-informative section contains the following headings:

  1. In Development
  2. Feedback
  3. Pricing

By clicking on the various categories, you can access the individual work areas.

Adhesive Joint App

Analytical calculation methods can be used in the Adhesive Joint App. In addition, predefined geometries that can be used for this purpose are listed, which can be selected in combination with the analytical calculation methods for a calculation process.

The following analytical methods can be applied:

  1. Bigwood & Crocombe (general elastic)

Categories of the analytical toolbox

The analytical toolbox consists of the following main categories:

  1. Choose your loadcase scenario
  2. Data entry
  3. Forces Overview
  4. Adherend / Adhesive Data
  5. Results - Plots
  6. Results - Data

Choose your loadcase scenario

The following geometries are currently available in the analytical toolbox:

  1. Manual (most general SLJ)
  2. Manual Single Lap (rectangle)
  3. Double-L-Bracket

By clicking on the button "More Information" the user gets more information about the use case.

The use case can be selected by clicking the "Use this Loadcase" button. When this button is clicked, the user is taken to the Data Entry area for the selected use case. All use cases are carried out step by step in a wizard, allowing the user to enter the data in clear input fields.

Once the calculation is done, more categories appear.

Data Entry

  1. Selection of use case „Manual (most general SLJ)“

    2. The wizard consists of three stages. Within the stages, the respective inputs are entered for the areas of the connection that are necessary to perform the calculation.

    1. Bonding Area
      1. Adhesive Selection
      2. Bonding Area Geometry Parameters
    2. Adherend Material Selection
      1. Adherend 1 (upper, fixed)
      2. Adherend 2 (lower)
    3. Loads
      1. Loads Face "F2"
      2. Loads Face "F3"
      3. Loads Face "F4"

  2. Selection of use case „Manual Single Lap (rectangle)“

    3. The wizard consists of three stages. Within the stages, the respective inputs are entered for the areas of the connection that are necessary to perform the calculation.

    1. Geometry
      1. Geometry Parameters
      2. Choose Adhesive
    2. Adherend Material Selection
      1. Adherend 1
      2. Adherend 2
    3. Loads
      1. Force Input

  3. Selection of use case „Double-L-Bracket“

    4. The wizard consists of three stages. Within the stages, the respective inputs are entered for the areas of the connection that are necessary to perform the calculation.

    1. Adherend Geometry
      1. Adherend 1 (upper, fixed)
      2. Shared Adherend Properties
      3. Adherend 2 (lower, for load introduction
    2. Adherend Material Selection
      1. Adherend 1: Isotropic / Composite definition
      2. Adherend 2: Isotropic / Composite definition
    3. Adhesive Information
      1. Adhesive Selection

Forces Overview

The overview of the internal forces is displayed as soon as the analytical calculation has been completed and the results have been uploaded to the results area.

The overview of the internal forces is listed in tabular form and consists of the User Input, Section 1, Section 2, Section 3 and Section 4 with the associated forces and moments. A picture with applied cutting forces illustrates the listed table.

Adherend / Adhesive Data

The Adherend / Adhesive Data category shows a table of the input data entered in the Data Entry category. It is used for overview and control of own inputs.

Results - Plots

The Results - Plots category displays two main plots for graphical visualization of the results on the bondline. By clicking on the legend directly above the graph, individual graphs can be hidden or displayed.

  1. Shear & Peel Stress Distribution: Bigwood & Crocombe (gen) Method

    2. The chart contains two different graphs, which can be displayed by the successfully performed calculation.

    The failure of the adhesive depends mainly on the distribution of the transverse normal (peel) and shear stresses along the bond line of the lap joint (SLJ). In an SLJ under tension and bending, these stresses vary greatly along the bond length, with peak values at the ends of the overlap. Their distribution can be efficiently calculated using the analytical methods offered.

  2. Adhesive Failure Criteria (e.g. Adhesive Tensile Strength: 26.0 MPa)

    3. The Adhesive Failure Criteria graph includes three different adhesive failure criteria, von Mises 3D, Drucker Pager and Tresca, which can be displayed by the successfully performed calculation.

    In addition, an IRF limit can be displayed on the graph and dynamically adjusted. The definition of IRF (Inverse Reserve Factor) can be found in the General Terms chapter. When evaluating adhesive bonds, reserve factors can help to estimate safety and durability. The material strength of the adhesive is analyzed using established failure criteria for brittle and ductile isotropic materials (e.g. von Mises yield criterion). By comparing the material strength of the adhesive with the corresponding equivalent stress of the failure criterion, an inverse reserve factor (IRF) is determined. It should always be less than 1, depending on the safety factors you have included in your design criteria.

Results - Data

  1. Presentation of results

    2. In the Results - Data category, the main IRFs of the performed calculation are summarized. Care must be taken to correctly interpret and evaluate the results of the calculation. The presentation of specific values on calcbond, especially with regard to Inverse Reserve Factors does not represent a general evaluation of the load bearing capacity of the connection, but is merely a factual description of the mathematical results, which are based on the input values of the user. Due to the simplifications used by the user on calcbond, even an IRF significantly smaller than 1 can lead to failure of the component.

  2. Result Management
    1. Save calculation

      2. The Save Calculation function saves the entire calculation, including date, input and result data, to My Calculation.

      1. Project name: Project
      2. Calculation name: Title
    2. Download PDF Report

      3. With the Download PDF button the calculation report can be requested and is immediately available for download.

      This can also be done after the calculation has been saved in My Calculation.

General tips on the Adhesive Joint Design work area

  1. All input fields are predefined with default values. These default values are entered in the fields and are visible. If these values are not changed, the platform calculates for the corresponding input with the pre-entered values.
  2. As long as no calculation has been started, entries are lost as soon as the wizard input area is left on the platform. This happens e.g. by clicking on the Wiki tab, or other areas on the platform.
  3. The wizard remembers any input made or changed after computing with the data set, as long as one remains in the analytical toolbox. In this way, multiple calculations can be performed in succession without having to re-enter all the data. Only the values to be varied can be adjusted to recalculate.
  4. The result of a calculation is lost as soon as it is recalculated. However, the user has the option to save the results on My Calculation with a project name and calculation title so that they can be retrieved at any time.
  5. In each calculation report generated in Results Management or My Calculation, a barcode is listed on the last page. This barcode also links directly to the calculation so that work can continue directly on the existing basis.

The workspace: AutoFEA

The AutoFEA workspace contains the input options for numerical simulations, which can be requested and processed by sending them from the calcbond platform to ar engineers GmbH.

Choose a Use Case for FEA request

  1. Bonded Stud
  2. Beam on Beam
  3. Bonded Tubes

General Terms

This chapter is not yet complete and will be added in future versions.