1.  Addition of 6 new nonlinear hysteretic models, in addition to the 4 existing models. In total, 10 different hysteretic models are now available which cover a wide range of nonlinear behavior (models 5-10 below are new):
      1.  Linear Elastic Model
      2.  Bilinear Plastic Model
      3.  Bilinear Plasticity Model with Bidirectional Coupling
      4.  Clough Bilinear Stiffness Degrading Model
      5.  Modified Clough Bilinear Stiffness Degrading Model 
      6.  Bilinear Elastic Model
      7.  Bilinear Flag Model
      8.  Origin-Oriented Bilinear Model
      9.  Peak-Oriented Bilinear Model
      10. Bilinear Slip Model

 

2.  Parallel processing support: Running spectral analysis in Bispec is now even much faster with support for multiple processors and multiple cores. For example, with two quad-core processors, spectral analysis can run close to 8 times faster, which is ideal for ground motion studies.

 

3.  Improved batch import of ground motion records: It is now possible to import a virtually unlimited number of ground motion records into a group in a single action, using the batch import feature.

 

4.  Expanded and re-written help documentation which includes detailed description of the user interface, internal implementation and hysteretic models.

 

5.  The main screen of the program was modified to simplify entry of analysis parameters and to include options for selecting and configuring the 6 new hysteretic models.

 

6.  Ability to define custom ranges of periods and frequencies, in addition to linearly or logarithmically spaced values.

 

7.  Improvement bidirectional constant-strength spectra. The user has now more control on specifying the strength in the second direction in constant-R and constant normalized strength spectra.

 

8.  Resolved problem with running bidirectional analysis in version 1.62.

 

9.  Resolved problem with hardening ratio in version 1.62.

 

10. Other minor changes and bug fixes.

 

Bispec Version 1.62 - 01/07/2009