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Despite increasing scale and scope of mass timber construction, we are still relying heavily on steel and concrete for lateral load resistance in wood buildings.  Timber braced frames have now been implemented in contemporary buildings and have strong historical precedent.  One system that I haven't seen discussed is a mass timber moment frame.  Perhaps there is good reason for this, but let's entertain the thought.  There are certainly instances where architects might want the openness of a portal frame in timber.  Do you think a timber moment frame is possible?  What are some technical concerns that would need to be addressed?

Here are a couple that come to mind:

 - Connection slip amplified over the depth of a beam or column could result in large rotations before engaging an attached member.  Anyone who's checked story drift on a light-frame shearwall with an unfavorable aspect ratio knows NDS can be very punishing in these applications.
 - Orthotropic properties could cause issues transferring moment between horizontal and vertical frame members. - Long-term cross-grain shrinkage could result in loss of restraint as bearing surfaces which are initially flush pull away.  Perhaps some sort of take-up device could be developed to prevent this?

Eager to hear everyone's thoughts!

Hi Christian, Definitively, timber should be a material to be considered more widely soon. Here I found this interesting video of what is being made in the USA: https://www.youtube.com/watch?v=gEewgo99tRc

The European experience (https://www.youtube.com/watch?v=x6JTJWY_uag) and East experience (joint or connections: https://www.youtube.com/watch?v=OJ8V_rzwxh0) should be noticed.

Regards,

AG

Despite increasing scale and scope of mass timber construction, we are still relying heavily on steel and concrete for lateral load resistance in wood buildings.  Timber braced frames have now been implemented in contemporary buildings and have strong historical precedent.  One system that I haven't seen discussed is a mass timber moment frame.  Perhaps there is good reason for this, but let's entertain the thought.  There are certainly instances where architects might want the openness of a portal frame in timber.  Do you think a timber moment frame is possible?  What are some technical concerns that would need to be addressed?

Here are a couple that come to mind:

 - Connection slip amplified over the depth of a beam or column could result in large rotations before engaging an attached member.  Anyone who's checked story drift on a light-frame shearwall with an unfavorable aspect ratio knows NDS can be very punishing in these applications.
 - Orthotropic properties could cause issues transferring moment between horizontal and vertical frame members. - Long-term cross-grain shrinkage could result in loss of restraint as bearing surfaces which are initially flush pull away.  Perhaps some sort of take-up device could be developed to prevent this?

Eager to hear everyone's thoughts!

Despite increasing scale and scope of mass timber construction, we are still relying heavily on steel and concrete for lateral load resistance in wood buildings.  Timber braced frames have now been implemented in contemporary buildings and have strong historical precedent.  One system that I haven't seen discussed is a mass timber moment frame.  Perhaps there is good reason for this, but let's entertain the thought.  There are certainly instances where architects might want the openness of a portal frame in timber.  Do you think a timber moment frame is possible?  What are some technical concerns that would need to be addressed?

Here are a couple that come to mind:

 - Connection slip amplified over the depth of a beam or column could result in large rotations before engaging an attached member.  Anyone who's checked story drift on a light-frame shearwall with an unfavorable aspect ratio knows NDS can be very punishing in these applications.
 - Orthotropic properties could cause issues transferring moment between horizontal and vertical frame members. - Long-term cross-grain shrinkage could result in loss of restraint as bearing surfaces which are initially flush pull away.  Perhaps some sort of take-up device could be developed to prevent this?

Eager to hear everyone's thoughts!

Check this out

https://www.skyscrapercentre.com/building/projekt-pi/39979

Greetings

Olaf

Despite increasing scale and scope of mass timber construction, we are still relying heavily on steel and concrete for lateral load resistance in wood buildings.  Timber braced frames have now been implemented in contemporary buildings and have strong historical precedent.  One system that I haven't seen discussed is a mass timber moment frame.  Perhaps there is good reason for this, but let's entertain the thought.  There are certainly instances where architects might want the openness of a portal frame in timber.  Do you think a timber moment frame is possible?  What are some technical concerns that would need to be addressed?

Here are a couple that come to mind:

 - Connection slip amplified over the depth of a beam or column could result in large rotations before engaging an attached member.  Anyone who's checked story drift on a light-frame shearwall with an unfavorable aspect ratio knows NDS can be very punishing in these applications.
 - Orthotropic properties could cause issues transferring moment between horizontal and vertical frame members. - Long-term cross-grain shrinkage could result in loss of restraint as bearing surfaces which are initially flush pull away.  Perhaps some sort of take-up device could be developed to prevent this?

Eager to hear everyone's thoughts!

Despite increasing scale and scope of mass timber construction, we are still relying heavily on steel and concrete for lateral load resistance in wood buildings.  Timber braced frames have now been implemented in contemporary buildings and have strong historical precedent.  One system that I haven't seen discussed is a mass timber moment frame.  Perhaps there is good reason for this, but let's entertain the thought.  There are certainly instances where architects might want the openness of a portal frame in timber.  Do you think a timber moment frame is possible?  What are some technical concerns that would need to be addressed?

Here are a couple that come to mind:

 - Connection slip amplified over the depth of a beam or column could result in large rotations before engaging an attached member.  Anyone who's checked story drift on a light-frame shearwall with an unfavorable aspect ratio knows NDS can be very punishing in these applications.
 - Orthotropic properties could cause issues transferring moment between horizontal and vertical frame members. - Long-term cross-grain shrinkage could result in loss of restraint as bearing surfaces which are initially flush pull away.  Perhaps some sort of take-up device could be developed to prevent this?

Eager to hear everyone's thoughts!

Christian,

I think there are many examples of glulam moment frames already. I know that extensive testing in Europe has been done on them. We have conducted some studies on moment connections with embedded steel plates.

I don't think CLT would be desirable for the frame parts since the two-way action of the cross-layers does not really contribute to frame stiffness. Glulam and LVL are much better choices.

Despite increasing scale and scope of mass timber construction, we are still relying heavily on steel and concrete for lateral load resistance in wood buildings.  Timber braced frames have now been implemented in contemporary buildings and have strong historical precedent.  One system that I haven't seen discussed is a mass timber moment frame.  Perhaps there is good reason for this, but let's entertain the thought.  There are certainly instances where architects might want the openness of a portal frame in timber.  Do you think a timber moment frame is possible?  What are some technical concerns that would need to be addressed?

Here are a couple that come to mind:

 - Connection slip amplified over the depth of a beam or column could result in large rotations before engaging an attached member.  Anyone who's checked story drift on a light-frame shearwall with an unfavorable aspect ratio knows NDS can be very punishing in these applications.
 - Orthotropic properties could cause issues transferring moment between horizontal and vertical frame members. - Long-term cross-grain shrinkage could result in loss of restraint as bearing surfaces which are initially flush pull away.  Perhaps some sort of take-up device could be developed to prevent this?

Eager to hear everyone's thoughts!

Despite increasing scale and scope of mass timber construction, we are still relying heavily on steel and concrete for lateral load resistance in wood buildings.  Timber braced frames have now been implemented in contemporary buildings and have strong historical precedent.  One system that I haven't seen discussed is a mass timber moment frame.  Perhaps there is good reason for this, but let's entertain the thought.  There are certainly instances where architects might want the openness of a portal frame in timber.  Do you think a timber moment frame is possible?  What are some technical concerns that would need to be addressed?

Here are a couple that come to mind:

 - Connection slip amplified over the depth of a beam or column could result in large rotations before engaging an attached member.  Anyone who's checked story drift on a light-frame shearwall with an unfavorable aspect ratio knows NDS can be very punishing in these applications.
 - Orthotropic properties could cause issues transferring moment between horizontal and vertical frame members. - Long-term cross-grain shrinkage could result in loss of restraint as bearing surfaces which are initially flush pull away.  Perhaps some sort of take-up device could be developed to prevent this?

Eager to hear everyone's thoughts!

Here in Kerala state, a single storey hall for using koothambalam (Malayalam). Two Timber trusses is taken the load of rafters and purlins of roofing including clay tiles. The Timber trusses are placed at the two ends 2metres away from short spans, thereby taking the 4 ridge rafters, at the four corners. The 2 shorter span carries triangular shape portion vertex at the top , longer span trapezoidal. If you are interested I may send the drawing of the wooden trusses wooden ties and struts connected with ms plates and bolts.

Despite increasing scale and scope of mass timber construction, we are still relying heavily on steel and concrete for lateral load resistance in wood buildings.  Timber braced frames have now been implemented in contemporary buildings and have strong historical precedent.  One system that I haven't seen discussed is a mass timber moment frame.  Perhaps there is good reason for this, but let's entertain the thought.  There are certainly instances where architects might want the openness of a portal frame in timber.  Do you think a timber moment frame is possible?  What are some technical concerns that would need to be addressed?

Here are a couple that come to mind:

 - Connection slip amplified over the depth of a beam or column could result in large rotations before engaging an attached member.  Anyone who's checked story drift on a light-frame shearwall with an unfavorable aspect ratio knows NDS can be very punishing in these applications.
 - Orthotropic properties could cause issues transferring moment between horizontal and vertical frame members. - Long-term cross-grain shrinkage could result in loss of restraint as bearing surfaces which are initially flush pull away.  Perhaps some sort of take-up device could be developed to prevent this?

Eager to hear everyone's thoughts!

Despite increasing scale and scope of mass timber construction, we are still relying heavily on steel and concrete for lateral load resistance in wood buildings.  Timber braced frames have now been implemented in contemporary buildings and have strong historical precedent.  One system that I haven't seen discussed is a mass timber moment frame.  Perhaps there is good reason for this, but let's entertain the thought.  There are certainly instances where architects might want the openness of a portal frame in timber.  Do you think a timber moment frame is possible?  What are some technical concerns that would need to be addressed?

Here are a couple that come to mind:

 - Connection slip amplified over the depth of a beam or column could result in large rotations before engaging an attached member.  Anyone who's checked story drift on a light-frame shearwall with an unfavorable aspect ratio knows NDS can be very punishing in these applications.
 - Orthotropic properties could cause issues transferring moment between horizontal and vertical frame members. - Long-term cross-grain shrinkage could result in loss of restraint as bearing surfaces which are initially flush pull away.  Perhaps some sort of take-up device could be developed to prevent this?

Eager to hear everyone's thoughts!

Wooden Truss is placed where the first rafter is starting on the vertex of the first triangle of the truss , longest rafter is at the middle. 

Despite increasing scale and scope of mass timber construction, we are still relying heavily on steel and concrete for lateral load resistance in wood buildings.  Timber braced frames have now been implemented in contemporary buildings and have strong historical precedent.  One system that I haven't seen discussed is a mass timber moment frame.  Perhaps there is good reason for this, but let's entertain the thought.  There are certainly instances where architects might want the openness of a portal frame in timber.  Do you think a timber moment frame is possible?  What are some technical concerns that would need to be addressed?

Here are a couple that come to mind:

 - Connection slip amplified over the depth of a beam or column could result in large rotations before engaging an attached member.  Anyone who's checked story drift on a light-frame shearwall with an unfavorable aspect ratio knows NDS can be very punishing in these applications.
 - Orthotropic properties could cause issues transferring moment between horizontal and vertical frame members. - Long-term cross-grain shrinkage could result in loss of restraint as bearing surfaces which are initially flush pull away.  Perhaps some sort of take-up device could be developed to prevent this?

Eager to hear everyone's thoughts!