Structural analysis of a buidling using Robot Structural Analysis

1) What are HVAC systems? Why are they essential in the modeling of buildings

HVAC refers to heating, ventilation and air conditioning which is used to move air between indoor and outdoor areas along with heating and cooling in the buildings. It regulates both air quality and temperature in the building. HVAC system goes hand in hand with architecture of the building and installation of HVAC fulfills energy code requirements of buildings. Maintenance on HVAC systems are also important such as replacement of filters, inspection of ducts, pipes, furnances annually to avoid damage.

Factors considered for HVAC are

• Sizing of system : Right size of HVAC ensures efficiency and gives better heating/cooling
• Availability of Heating or cooling solutions : Different types of HVAC solutions for various operations and buildings
• Mechanical performance : Better mechanical performance gives energy efficient model with minimal cost. Energy management using computer control that monitor and control building's HVAC systems. Automatic control features such as adjustment of air temperature based on indoor and outdoor humidity.
• Equipment locations : Correct elevation and Correct location of HVAC system for better perfomance

Considerations for designing HVAC

• Lighting and air circulation
• Controlling temperature
• Humidity
• Space required
• Calculations for efficiency
• Cost
• Buidling standards and codes
• Obstructions with structural members
• Requirments from client

HVAC is essential in the modeling of building because :

• It helps to control temperature, humidity and air quality
• It improves productivity in working areas such as office by providing comfortable environment
• By improving air quality in building, it helps human with appropriate breathing and maintain good health
• If HVAC system is not installed properly, can lead to increase in cost of energy bill for cooling the place in summer and heating the place in winter.

2) From week 7 assignment, based on the building designed use the same Revit file to design a HVAC system for each floor to cover the topics included in the class.
a. Typical HVAC unit includes Distribution center
b. Collector
c. Ducts
d. Blower
Based on the layout choose appropriate ducts and elevation using property browser and assign the components to appropriate groups to complete modeling of the HVAC unit

AIM : To create HVAC system on each floor of the building

INTRODUCTION : HVAC in residential buildings are quiet different from office or commercial areas as more number of people involved and equipment need to generate more heat making air conditioning or recirculation of air.

HVAC units :

• Distribution center : Serves as pathway for energy to travel from HVAC equipment to different parts of building
• Collector : Return air is collected and exhausted to replace fresh air
• Ducts : Acts like medium which transfers energy from one place to another
• Blower : Create air flow thorugh the system

PROCEDURE :

• Open revit
• Open new project with mechanical template
• Link previous revit project to the current project
• Copy monitor the multiple items and click on finish
• Go to systems tab
• Click on air terminal and select supplier diffuser
• Place supply diffuser in all the rooms
• Similarly place return diffuser in all the rooms
• Now place Air handling units and connect it with ducts to supplier diffuser and return diffuser on each room
• Place exhaust centrifugal fan in every bathroom

RESULTS

GROUND FLOOR

FIRST FLOOR

SECOND FLOOR

3) Use the add-ins tab to load plug-ins for robot structural analysis to your Revit software

AIM : To install robot structural analysis in revit software

INTRODUCTION : Robot structural analysis is a structural load analysis that verifies code compliance and uses BIM integrated workflows to exchange data with revit. It helps to create more resilient, constructible designs that are accurate, coordinated and connected to BIM.

PROCEDURE :

• Click on cart which is beside account details in revit software
• Download Structural analysis toolkit and install it
• Now Sign in to Autodesk account in google
• Go to products
• Download robot structural analysis professional and install it
• Open revit and go to analyze tab
• Robot structural analysis is installed

RESULT :

4) Why do we need to assess buildings/analyze while modeling elements? Does design affect modeling in anyways?

While modeling elements of a building, structural analysis is necessary for improving design accuracy, analyszing the effect of structural loads and creating more resilient and sustainable designs. Structural analysis of a building represents technical representation of a system which helps to design a structure with proper strength, safety and rigidity.

Factors which play role in structural analysis are

• Geometry : Geometry of building that is shape, orientation etc helps to understand basic primary criteria of design
• Material : Material such concrete and steel widely used for constructions. These are load resistant material and acts as a major role where magnitude of loads are high on buildings.
• Properties : Understanding mechanical properties of material based on how it performes under different condition, how it response to loads, learning about its failure criteria so that design is carried out efficiently.
• Serviceability : The function of building and performance of building under service loads.
• Loads : Understanding types of loads acting on the building and also future developmental loads acting on the building. Design of columns, beams, slabs depends upon the load acting on the building
• Performance : In response to loads the perfomance of the building is calculated that is when loads acting on the building, the response is calculated in force or displacement method in the form of bending moment diagram, shear force diagram or deflection diagram which helps to analyse and design building.
• Design : Designing a building based on both architectural design and structural analysis which results in more resilient and sustainable type of building.

Design is the idea for function and shape of building, on the other hand modeling (analysis of model) makes sure design works under various loads, materials and boundary conditions. Therefore design and modeling go hand in hand which makes efficient structural element. Software such as Revit software supports the BIM process for structural engineers by providing the physical and analytical model of the structure. The physical model used for construction documentation, shop drawing and fabrication. The associated analytical model is used for structural analysis and code checking design. It contains all structural attributes and properties that are needed during this process such as structural material properties, boundary conditions and structural loads.

5) From the structural model developed in week 6 and 7, export the complete analytical model to robot structural analysis.

a. List your assumptions on what boundary conditions will be realistic for the analysis approach

b. Use the design standards to decide what loads must be applied to floorings based on the type of structure decided

c. List the load combinations and include them in the analysis model

d. Analyze the building and report the following results

i. Maximum Moment in each floor for all Load Combinations

ii. Maximum Displacement in each floor for all Load combinations

iii. Lateral Displacement in building for all Lateral Load combinations

e. After analysis, do you think you have a better approach or idea in modeling structural members?

AIM : To export model to robot structural analysis and to carryout the structural analysis of model

INTRODUCTION : Robot structural analysis is a structural load analysis that verifies code compliance and uses BIM integrated workflows to exchange data with revit. It helps to create more resilient, constructible designs that are accurate, coordinated and connected to BIM.

1. There are three boundary conditions Fixed, Pinned and Roller. In this project boundary condition is taken as fixed as model should be connected to rigid body which is ground. Pinned and Roller condition leads to rotation of model which is not recommended in this case.
2. Load combinations are taken as per IS 456 : 2000 limit state of serviceability
3. Load combinations are Load combination 1:1DL+0.8LL+0.8 WL and Load combination 2:1DL+0.8LL+0.8SEIS1

PROCEDURE :

• Open week 7 structural model project
• Go to 3D views of analytical model
• 
• Select structural settings in manage tab
• Click on add in load combination and also edit selected formula, enter DL with factor 1
• Again click on add in edit selected formula enter LL with factor 0.8
• Again click on add in edit selected formula enter WL with factor 0.8
  
  
• 
• Now add another load combination as shown below
• 
• Click on analyse tab and select boundary conditions
• Select point and state is fixed
• Select the bottom of columns
• Go to level 1 analytical
• Go to analyse tab and Select load : Area load
• Select dead load in properties and select the area for the load application on each floor
• Click finish
• Similarly create live load and wind loads in each floor (Load combination1)
• Change Fz of each load according to the model
• Similarly add loads according load combination 2
• 
• Click on analyse tab
• Click on robot structural analysis
• 
• Click on calculations
• Click on displacements and note down displacement readings
• Click on Diagrams for members to display forces and bending moment

RESULTS :

• i. Maximum Moment in each floor for all Load Combinations
  
  
• 
• 
• ii. Maximum Displacement in each floor for all Load combinations
  
  
• 
• iii. Lateral Displacement in building for all Lateral Load combinations
  
  
• 

e) After analysis, do you think you have a better approach or idea in modeling structural members?

Robot structural analysis is a good structural analysis software, other softwares such as STAAD PRO is used for structural analysis

6) What is energy analysis and why do we need to consider it while modeling in Revit? How does the factor of sustainability improve the quality of your design?

Energy analysis of a building is a study of energy consumed by the building during construction and operation of the building. Due to rapid urbanization mechanical equipments usage maximised for active cooling or heating, resulting increase in greenhouse gases. This situation led to promote energy efficient solutions for building. Energy analysis helps to understand movement of energy in and out throughout the buildings. This information helps designers to understand levels of energy is created in the building and to make cost effective decisions that improves performance of building. Energy analysis measures expected energy use based on buildings geometry, climate, building type, envelope properties and active systems (HVAC and Lighting).

Four steps to calculate energy analysis

• Load calculation - Calculation of gain or loss of energy of building
• System calculation - Calculation of energy ned to be added or extracted that is supplied by HVAC systems
• Plant calculation - Determination of requirements of equipments
• Cost calculation - Cost of equipments which are choosen based on sustainable alternatives

Using BIM tools such as revit is used to evaluate energy analysis of a building and these tools are useful to plan, design, construct efficiently and manage building infrastructure. It assists to design different alternatives for the design of building at conceptual stage so that effective energy strategies are attained within building constraints. To perform building energy analysis for revit models, energy optimization in analysis tab is used to create energy model which is connected to autodesk green building studio for energy analysis.

Green building studio is autodesk core energy analysis engine. This flexible cloud-based service uses DOE2 simulation engine. It allows to run building performance simulation to optimize energy efficiency and to work toward carbon neutrality in design process. Green building studio helps to design high performance building within less time and less cost.

Sustainability factor in the building design improves air quality in building, it helps human with appropriate breathing and maintain good health. It also helps to reduce green house gas emissions of building by using less energy. This type of model is considered as green building. Software tools helps reduce dependency on mechanical equipments through various strategies and helps to make sustainable alternative which saves time, money and energy effiecient design of building.